Major interaction on record — check this product against your medications before combining. Based on 7 of 14 ingredients. Check your meds →
Dietary supplement

Return to Youth Ingredients & Drug Interactions

by Ron Teeguarden's Dragon Herbs

Return to Youth label
See full label image
Capsule Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Return to Youth against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Return to Youth is a dietary supplement by Ron Teeguarden's Dragon Herbs with 14 active ingredients. Its ingredients are commonly taken for general antioxidant support, eye health, immune support.Based on those ingredients, 1,334 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Goji Berry Extract, Schizandra fruit extract, Fennel Fruit Extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Return to Youth by Ron Teeguarden's Dragon Herbs

Ask about any prescription or over-the-counter medication and we check it for interactions with Return to Youth by Ron Teeguarden's Dragon Herbs — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Return to Youth by Ron Teeguarden's Dragon Herbs

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 14 active ingredients.
  • “Proprietary Extract Blend” is a proprietary blend — the label gives one combined amount (1,500 mg) without saying how much of each component you get.

Return to Youth contains 14 ingredients, 8 of which we could evaluate for interactions. The active herbal extracts include goji berry, schisandra fruit, rehmannia root, poria mushroom (a medicinal fungus), and fennel fruit, along with several traditional Chinese medicine botanicals: achyranthes root, morinda root, eucommia bark, Chinese yam rhizome, cornus fruit, polygala root, cistanche stem, and broussonetia fruit.

The product also includes inactive ingredients—pullulan (a plant-based capsule material), rice powder, bamboo extract powder, and a rice extract blend—which are fillers and binders that hold the capsule together.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use.

Why this rating?
  • The label markets this product for: Jing tonic for vitality and well-being.
  • We looked for evidence on: Aging, Chronic fatigue syndrome (CFS), Stress, Quality of life, Longevity, Vitality — and 2 related terms.
  • The closest evidence on file: Poria Mushroom is rated "Insufficient Reliable Evidence To Rate" for Chronic fatigue syndrome (CFS) (Natural Medicines).
  • Also on file: Schisandra is rated "Insufficient Reliable Evidence To Rate" for Stress, Aging.
  • Also on file: Goji is rated "Insufficient Reliable Evidence To Rate" for Quality of life.

The evidence we hold shows insufficient reliable data to rate most of the active ingredients in this formula. Goji berry has not established effectiveness for sunburn, cardiovascular disease, high blood pressure, obesity, or quality of life.

Schisandra has insufficient evidence for asthma, athletic performance, cough, diabetes, diarrhea, or hepatitis. Rehmannia is possibly effective for chronic kidney disease, but the evidence is insufficient for aplastic anemia, atopic disease, osteoporosis, diabetes, and diabetic kidney damage.

Poria mushroom, fennel, and the other extracts lack established effectiveness ratings in our data. Fennel alone is possibly effective for menstrual cramps.

Because this is a multi-ingredient blend with mostly unproven claims, you should talk with your pharmacist or doctor about whether it suits your goals.

The evidence, ingredient by ingredient Goji Schisandra Ba Ji Tian American Dogwood Rehmannia Poria Mushroom Fennel

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 4 of the 7 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 7 of 7.
  • General safety write-ups exist for 7 of 7.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Goji berry is generally well tolerated as a food but concentrated supplements have less safety data. Rare cases of liver injury and allergic reactions—including severe swelling of the face and throat (angioedema) and anaphylaxis—have been reported.

Schisandra is generally well tolerated in the short term, though high-quality data are limited; the most common side effects are decreased appetite, heartburn, and stomach upset. Rehmannia has limited human safety data and varies in quality between products.

Poria mushroom is generally well tolerated in traditional use, but human safety data are limited; rare allergic reactions including allergic rhinitis and asthma have occurred. Fennel seems well tolerated as food but concentrated supplements need more caution; side effects can include stomach upset, photosensitivity (sun sensitivity), and allergic reactions; rare cases of seizures and bronchial asthma have been reported.

For pregnancy, goji and fennel should be avoided in medicinal amounts due to limited data and possible hormone-like or uterine effects. Schisandra, rehmannia, and poria mushroom should be avoided in pregnancy due to insufficient safety information.

For breastfeeding, caution is advised with goji and fennel; schisandra, rehmannia, and poria mushroom should be avoided.

Side effects, ingredient by ingredient Goji Schisandra Ba Ji Tian American Dogwood Rehmannia Poria Mushroom Fennel

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 6 of the 7 matched ingredients can interact with medications — Poria Mushroom, Fennel, Schisandra, Ba Ji Tian, Goji, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications.
  • For scale: 1,335 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check any blood thinner (anticoagulant) you take—especially warfarin—any drug your liver processes via CYP enzymes (a large group including many common medicines), any blood pressure or diabetes medication, any sedative, antibiotic (especially ciprofloxacin), heart rhythm drug, immune suppressant (tacrolimus), antifungal (voriconazole), and any cancer drug or contraceptive. The ingredients we could not fully evaluate may carry additional risks we cannot assess.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.

This traditional Chinese herbal blend is not established to treat any condition in the data we hold. If you take blood thinners, heart medications, diabetes or blood pressure drugs, sedatives, antibiotics, or cancer medications, you must check your exact prescriptions with the tool below before starting.

Pregnant or breastfeeding individuals should talk with their pharmacist or doctor first.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 7 of 14 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 22, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Return to Youth, straight from the product label.

Brand Ron Teeguarden's Dragon Herbs
Barcode (UPC) 679372003201
Net contents 100 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Aug 22, 2024
DSLD ID 316932
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Return to Youth by Ron Teeguarden's Dragon Herbs, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
3 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
Servings per container
33
UPC/BARCODE
679372003201
IngredientAmount% DV
Goji Berry Extract0 NP--
Schizandra fruit extract0 NP--
Achyranthes Root Extract0 NP--
Proprietary Extract Blend1500 mg--
Morinda root extract0 NP--
Eucommia bark extract0 NP--
Chinese Yam rhizome extract0 NP--
Cornus Fruit Extract0 NP--
Polygala root extract0 NP--
Rehmannia Root Extract0 NP--
Poria sclerotium extract0 NP--
Cistanche Stem Extract0 NP--
Fennel Fruit Extract0 NP--
Broussonetia Fruit Extract0 NP--
Red Jujube Fruit extract0 NP--

Other ingredients: Pullulan Polysaccharide, Rice, Powder, Bamboo Extract, Powder, Rice extract Blend

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formula

"Return to Youth" is one of the greatest of all tonic formulations, and is in particular a superb Jing (Primal Essence) tonic.

Return to Youth 100 Vegetarian Capsules, 500 mg each

Pullulan caps - 100% natural, water-soluble polysaccharide produced through a fermentation process; vegetable origin; non-GMO; no starch, preservatives or chemical modifications; gluten free.

Formulation

This formulation is extremely safe and effective.

Pullulan caps - 100% natural, water-soluble polysaccharide produced through a fermentation process; vegetable origin; non-GMO; no starch, preservatives or chemical modifications; gluten free.

FDA Disclaimer Statement

These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.

Brand IP Statement(s)

Ron Teeguarden's Dragon Herbs Health Deserves Cultivation

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: Take 3 capsules, 2 times per day or as directed by a healthcare professional.

Precautions

Keep out of the reach of children.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Return to Youth by Ron Teeguarden's Dragon Herbs label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Return to Youth label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Return to Youth by Ron Teeguarden's Dragon Herbs

These are the 14 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container33 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Proprietary Extract Blend

1500 mg per serving

Other (inactive) ingredients: Pullulan Polysaccharide, Rice, Powder, Bamboo Extract, Powder, Rice extract Blend. These complete the product’s ingredient list but are not active constituents.

Interaction report

Return to Youth by Ron Teeguarden's Dragon Herbs Drug Interactions

Want to check YOUR meds against Return to Youth?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1,334Drugs
2 Major 1,332 Moderate

Ingredients driving the most interactions

Goji Berry Extract 1,000
Schizandra fruit extract 803
Fennel Fruit Extract 740
Poria sclerotium extract 417
Rehmannia Root Extract 258

Individual Drug Interactions

The ingredients in Return to Youth interact with 1,334 drugs. Click any drug to see the details.

6 of the 14 ingredients in Return to Youth interact with drugs. Each result below shows which ingredient is responsible. Goji Berry Extract Schizandra fruit extract Fennel Fruit Extract Poria sclerotium extract Rehmannia Root Extract Morinda root extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Return to Youth with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Goji Berry Extract8 drug types · 1,000 drugs

Warfarin (Coumadin)

Goji can increase the effects of warfarin and possibly increase the risk of bleeding.
There are at least 5 case reports of increased international normalized ratio (INR) in patients stabilized on warfarin who began drinking goji juice, concentrated goji tea, or goji wine. Goji may inhibit the metabolism of warfarin by cytochrome P450 2C9 (CYP2C9).

Likelihood Probable Evidence D
Antihypertensive Drugs

Theoretically, concomitant use of goji root bark, but not goji fruit, with antihypertensive drugs might have additive effects.
Animal and in vitro research suggest that goji root bark has hypotensive effects. However, goji fruit juice does not appear to reduce systolic or diastolic blood pressure in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, goji berry might inhibit CYP2C19 and reduce metabolism of CYP2C19 substrates.
In vitro research shows that goji berry tincture and juice inhibit CYP2C19 enzymes. Concomitant use with goji may decrease metabolism and increase levels of CYP2C19 substrates. However, this has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, goji berry might inhibit CYP2C9 and reduce metabolism of CYP2C9 substrates.
In vitro research shows that goji berry tincture and juice inhibit CYP2C9 enzymes. Additionally, multiple case reports suggest that goji berry concentrated tea and juice inhibit the metabolism of warfarin, a CYP2C9 substrate. Concomitant use with goji may decrease metabolism and increase levels of CYP2C9 substrates.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, goji berry might inhibit CYP2D6 and reduce metabolism of CYP2D6 substrates.
In vitro research shows that goji berry juice inhibits CYP2D6 enzymes. Concomitant use with goji may decrease metabolism and increase levels of CYP2D6 substrates. However, this has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, goji berry might inhibit CYP3A4 and reduce metabolism of CYP3A4 substrates.
In vitro research shows that goji berry juice inhibits CYP3A4 enzymes. Concomitant use with goji may decrease metabolism and increase levels of CYP3A4 substrates. However, this has not been reported in humans.

Likelihood Possible Evidence D
Flecainide (Tambocor)

Theoretically, goji berry might increase the levels and clinical effects of flecainide.
In one case report, a 75-year-old patient stable on flecainide and warfarin presented to the emergency room with fainting and pleomorphic arrhythmia caused by flecainide toxicity. Flecainide toxicity was attributed to drinking 1-2 glasses of concentrated goji tea daily for 2 weeks. Theoretically, goji may have inhibited the cytochrome P450 2D6 (CYP2D6) metabolism of flecainide.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, concomitant use of goji fruit polysaccharides or goji root bark with antidiabetes drugs might have additive effects.
Animal and in vitro research show that goji root bark and fruit polysaccharides might have hypoglycemic effects. However, clinical research has only shown that taking goji fruit polysaccharides with or without antidiabetes drugs modestly reduces postprandial glucose when compared with control, with no reports of hypoglycemia.

Likelihood Possible Evidence B
Goji Berry Extract full monograph & interactions

Schizandra fruit extract12 drug types · 803 drugs

Cyclophosphamide

Theoretically, schisandra might increase the levels and clinical effects of cyclophosphamide.
In vitro research shows that schisandra increases the concentration of cyclophosphamide, likely through inhibition of cytochrome P450 3A4. After multiple doses of the schisandra constituents schisandrin A and schisantherin A, the maximum concentration of cyclophosphamide was increased by 7% and 75%, respectively, while the overall exposure to cyclophosphamide was increased by 29% and 301%, respectively.

Likelihood Probable Evidence D
Cyclosporine (Neoral, Sandimmune)

Schisandra can increase the levels and clinical effects of cyclosporine.
A small observational study in children with aplastic anemia found that taking schisandra with cyclosporine increased cyclosporine trough levels by 93% without increasing the risk of adverse events. However, the dose of cyclosporine was reduced in 9% of children to maintain appropriate cyclosporine blood concentrations.

Likelihood Probable Evidence B
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, schisandra might increase the levels and clinical effects of CYP2C19 substrates.
In vitro research shows that schisandra inhibits CYP2C19, and animal research shows that schisandra increases the concentration of voriconazole, a CYP2C19 substrate. Theoretically, schisandra may also inhibit the metabolism of other CYP2C19 substrates. This effect has not been reported in humans.

Likelihood Probable Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, schisandra might decrease the levels and clinical effects of CYP2C9 substrates.
In vitro and animal research suggests that schisandra induces CYP2C9 enzymes. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Schisandra can increase the levels and clinical effects of drugs metabolized by CYP3A4.
Most clinical and laboratory research shows that schisandra, administered either as a single dose or up to twice daily for 14 days, inhibits CYP3A4 and increases the concentration of CYP3A4 substrates such as cyclophosphamide, midazolam, tacrolimus, and talinolol. Although one in vitro and animal study shows that schisandra may induce CYP3A4 metabolism, this effect appears to be overpowered by schisandra's CYP3A4 inhibitory activity and has not been reported in humans.

Likelihood Probable Evidence D
Midazolam (Versed)

Schisandra can increase the levels and clinical effects of midazolam.
A small pharmacokinetic study in healthy adults shows that taking schisandra extract (Hezheng Pharmaceutical Co.) containing deoxyschizandrin 33.75 mg twice daily for 8 days and a single dose of midazolam 15 mg on day 8 increases the overall exposure to midazolam by about 119%, increases the peak plasma level of midazolam by 86%, and decreases midazolam clearance by about 52%. This effect has been attributed to inhibition of CYP3A4 by schisandra.

Likelihood Probable Evidence B
P-Glycoprotein Substrates

Schisandra might increase the levels and clinical effects of P-glycoprotein substrates.
In vitro research shows that schisandra extracts and constituents such as schisandrin B inhibit P-glycoprotein mediated efflux in intestinal cells and in P-glycoprotein over-expressing cell lines. Additionally, a small clinical study shows that schisandra increases the peak concentration and overall exposure to talinolol, a P-glycoprotein probe substrate. Theoretically, schisandra might inhibit the efflux of other P-glycoprotein substrates.

Likelihood Possible Evidence D
Sirolimus (Rapamune)

Schisandra can increase the levels and clinical effects of sirolimus.
A small pharmacokinetic study in healthy volunteers shows that taking 3 capsules of schisandra (Hezheng Pharmaceutical Company) containing a total of 33.75 mg deoxyschizandrin twice daily for 13 days and then taking a single dose of sirolimus 2 mg increases the overall exposure and peak level of sirolimus by two-fold. This effect is thought to be due to inhibition of cytochrome P450 3A4 by schisandra, as well as possible inhibition of the P-glycoprotein drug transporter.

Likelihood Probable Evidence B
Tacrolimus (Prograf)

Schisandra can increase the levels and clinical effects of tacrolimus.
Clinical research in healthy children and adults, transplant patients, and patients with nephrotic syndrome and various rheumatic immunologic disorders shows that taking schisandra with tacrolimus increases tacrolimus peak levels by 183% to 268%, prolongs or delays time to peak tacrolimus concentrations, increases overall exposure to tacrolimus by 126% to 343%, and decreases tacrolimus clearance by 19% to 73%. This effect is thought to be due to inhibition of P-glycoprotein drug transporter and CYP3A4 and CYP3A5 by schisandra. Some clinical and observational studies suggest that schisandra increases tacrolimus levels similarly in both expressors and non-expressors of CYP3A5, while other studies suggest it does so to a greater degree in CYP3A5 expressors than non-expressors. Animal research suggests that the greatest increase in tacrolimus levels occurs when schisandra is taken either concomitantly or up to 2 hours before tacrolimus, and clinical and observational research in humans suggests that schisandra may increase whole blood levels of tacrolimus and decrease clearance of tacrolimus in a dose-dependent manner.

Likelihood Probable Evidence B
Talinolol

Schisandra can increase the levels and clinical effects of talinolol.
A small pharmacokinetic study in healthy volunteers shows that taking schisandra extract 300 mg twice daily for 14 days with a single dose of talinolol 100 mg on day 14 increases the peak talinolol level by 51% and the overall exposure to talinolol by 47%. This effect is thought to be due to the possible inhibition of cytochrome P450 3A4 and P-glycoprotein by schisandra. tly.

Likelihood Probable Evidence B
Voriconazole (Vfend)

Theoretically, schisandra might increase the levels and clinical effects of voriconazole.
Animal research shows that oral schisandra given daily for 1 or 14 days increases levels of intravenously administered voriconazole, a cytochrome P450 (CYP) 2C19 substrate. This effect is thought to be due to inhibition of CYP2C19 by schisandra. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, schisandra might decrease the levels and clinical effects of warfarin.
Animal research suggests that oral schisandra extract, given daily for 6 days, reduces levels of intravenously administered warfarin. This effect might be due to the induction of cytochrome P450 (CYP) 2C9 metabolism by schisandra. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Schizandra fruit extract full monograph & interactions

Fennel Fruit Extract6 drug types · 740 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, fennel might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.

Animal research suggests that fennel oil has antithrombotic and antiplatelet effects.

Likelihood Possible Evidence D
Ciprofloxacin (Cipro)

Theoretically, fennel might decrease the levels and clinical effects of ciprofloxacin.

Animal research shows that fennel reduces ciprofloxacin bioavailability by nearly 50%, possibly due to the metal cations such as calcium, iron, and magnesium contained in fennel. This study also found that fennel increased tissue distribution and slowed elimination of ciprofloxacin.

Likelihood Probable Evidence D
Contraceptive Drugs

Theoretically, taking large amounts of fennel might decrease the effects of contraceptive drugs due to competition for estrogen receptors.

Some constituents of fennel have estrogenic activity.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, fennel might increase levels of drugs metabolized by CYP3A4.

In vitro research suggests that fennel inhibits CYP3A4 enzyme activity. This effect has not been reported in humans.

Likelihood Possible Evidence D
Estrogens

Theoretically, taking large amounts of fennel might interfere with hormone replacement therapy due to competition for estrogen receptors.

Some constituents of fennel have estrogenic activity.

Likelihood Possible Evidence D
Tamoxifen (Nolvadex)

Theoretically, taking large amounts of fennel might decrease the antiestrogenic effect of tamoxifen.

Some constituents of fennel have estrogenic activity, which may interfere with the antiestrogenic activity of tamoxifen.

Likelihood Possible Evidence D
Fennel Fruit Extract full monograph & interactions

Poria sclerotium extract3 drug types · 417 drugs

Anticholinergic Drugs

Theoretically, poria mushroom might decrease the clinical effects of anticholinergic drugs.
In animal research, poria mushroom essential oil reduces acetylcholinesterase activity. This interaction has not been shown in humans.

Likelihood Possible Evidence D
Cholinergic Drugs

Theoretically, poria mushroom might have additive effects when used with cholinergic drugs.
In animal research, poria mushroom essential oil reduces acetylcholinesterase activity. This interaction has not been shown in humans.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, taking poria mushroom extract may enhance the therapeutic and adverse effects of sedatives.
Animal research shows that poria mushroom extract has sedative properties. This interaction has not been shown in humans.

Likelihood Possible Evidence D
Poria sclerotium extract full monograph & interactions

Rehmannia Root Extract2 drug types · 258 drugs

Antidiabetes Drugs

Theoretically, rehmannia might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research shows that rehmannia may have hypoglycemic effects.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, rehmannia might increase the risk of hypotension when taken with antihypertensive drugs.
Animal research shows that rehmannia may have hypotensive effects. Laboratory research shows that formulations of dried and processed rehmannia root inhibit angiotensin-converting enzyme (ACE).

Likelihood Possible Evidence D
Rehmannia Root Extract full monograph & interactions

Morinda root extract1 drug type · 86 drugs

Antidiabetes Drugs

Animal research shows that taking ba ji tian extracts might increase or decrease blood glucose levels. Theoretically ba ji tian might have additive effects or attenuate the effects antidiabetes drugs. Monitor blood glucose levels closely; dose adjustments of antidiabetes drugs might be necessary. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others.

Likelihood Possible Evidence D
Morinda root extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Return to Youth, from the product label.

Ron Teeguarden's Dragon Herbs

See all Ron Teeguarden's Dragon Herbs products
Name
Ron Teeguarden's Dragon Herbs
City
Los Angeles
State
CA
ZipCode
90036
Phone Number
(888) 558-6642
Web Address
www.dragonherbs.com
Pharmacist Counseling Corner

Return to Youth by Ron Teeguarden's Dragon Herbs: Common Questions

Does Return to Youth by Ron Teeguarden's Dragon Herbs interact with any medications?
Yes. Based on its ingredients, Return to Youth has a known interaction with 1,334 medications, including 2 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Return to Youth contains 14 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is goji berry safe to take with warfarin or other blood thinners?
No. Goji berry extract can boost warfarin's effects and raise bleeding risk, backed by at least five case reports. If you take a blood thinner, you must check with your pharmacist before starting this product.
Can I take this if I'm pregnant?
No. Goji and fennel should be avoided in medicinal amounts during pregnancy due to limited safety data and possible hormone-like or uterine effects. Schisandra, rehmannia, and poria mushroom also lack enough safety information in pregnancy. Talk with your doctor or pharmacist for personalized advice.
What does goji berry do in this formula?
Goji berry is a traditional Chinese tonic used for general vitality, but we hold insufficient evidence to establish that it works for specific conditions like cardiovascular health, blood pressure, or obesity.
What are the most common side effects?
Schisandra may cause decreased appetite, heartburn, and stomach upset. Fennel can cause gastrointestinal discomfort and photosensitivity. Rare allergic reactions, including severe swelling of the throat and anaphylaxis, have been reported with goji berry.
Can I take this with my diabetes or blood pressure medication?
Maybe, but you need to check first. Both goji and rehmannia may lower blood sugar or blood pressure, potentially adding to your medication's effect. Run your exact medicines through the checker on this page before starting.
What does this product actually treat?
The evidence we hold does not establish that this blend treats any specific condition. Rehmannia is possibly effective for chronic kidney disease, and fennel is possibly effective for menstrual cramps, but most ingredients lack proven effectiveness in our data.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Return to Youth label
Go deeper

The Full Monographs Behind Return to Youth’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Goji

Interacts with 1,000 drugs

Goji berries are a nutritious fruit rich in antioxidants, vitamins, and plant polysaccharides, and they are safe for most people as a food. While they are popular for eye health, immune supp...

Read the full Goji monograph → Herb & supplement monograph

Schisandra

Interacts with 803 drugs

Schisandra is a traditional Chinese medicine berry used as an adaptogen for stress, fatigue, and liver support. Human evidence is limited and most claims are not well proven, but it appears...

Read the full Schisandra monograph → Herb & supplement monograph

Ba Ji Tian

Interacts with 86 drugs

Ba Ji Tian is a root used in Traditional Chinese Medicine, mostly to 'tonify the kidneys' and support energy, sexual function, and bone health. Modern evidence in humans is very limited, and...

Read the full Ba Ji Tian monograph → Herb & supplement monograph

American Dogwood

American Dogwood is a North American flowering tree whose bark was used in traditional folk medicine, especially as a substitute for quinine to treat fevers. There is very little modern huma...

Read the full American Dogwood monograph → Herb & supplement monograph

Rehmannia

Interacts with 258 drugs

Rehmannia is a root used for centuries in Traditional Chinese Medicine, often to 'tonify' the kidneys and support energy or blood health. Human evidence for most modern uses is limited, so i...

Read the full Rehmannia monograph → Herb & supplement monograph

Poria Mushroom

Interacts with 417 drugs

Poria mushroom (Fu Ling) is a fungus long used in Traditional Chinese Medicine, mainly as a mild diuretic and digestive and calming aid. Modern scientific evidence in humans is very limited,...

Read the full Poria Mushroom monograph → Herb & supplement monograph

Fennel

Interacts with 740 drugs

Fennel is a Mediterranean herb widely used as a food and spice, and traditionally taken for digestive complaints, colic, and menstrual cramps. Some small studies suggest possible benefit for...

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Sources

Sources & How We Checked

Return to Youth's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 66 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Goji 14 references
  1. Huang KC. The Pharmacology of Chinese Herbs. 2nd ed. Boca Raton, FL: CRC Press, LLC 1999.
  2. Lam AY, Elmer GW, Mohutsky MA. Possible interaction between warfarin and Lycium Barbarum. Ann Pharmacother 2001;35:1199-201.
  3. Leung H, Hung A, Hui AC, Chan TY. Warfarin overdose due to the possible effects of Lycium barbarum L. Food Chem Toxicol 2008;46:1860-2. PubMed
  4. Amagase H, Nance DM. A randomized, double-blind, placebo-controlled, clinical study of the general effects of a standardized Lycium barbarum (goji) juice, GoChi. J Altern Complement Med 2008;14:403-12.
  5. Rivera, C. A., Ferro, C. L., Bursua, A. J., and Gerber, B. S. Probable interaction between Lycium barbarum (goji) and warfarin. Pharmacotherapy 2012;32(3):e50-e53.
  6. Monzon, Ballarin S., Lopez-Matas, M. A., Saenz, Abad D., Perez-Cinto, N., and Carnes, J. Anaphylaxis associated with the ingestion of Goji berries (Lycium barbarum). J.Investig.Allergol.Clin.Immunol. 2011;21(7):567-570.
  7. Franco, M., Monmany, J., Domingo, P., and Turbau, M. [Autoimmune hepatitis triggered by consumption of Goji berries]. Med.Clin.(Barc.) 9-22-2012;139(7):320-321.
  8. Jiménez-Encarnación E, Ríos G, Muñoz-Mirabal A, Vilá LM. Euforia-induced acute hepatitis in a patient with scleroderma. BMJ Case Rep 2012;2012. PubMed
  9. Larramendi CH, García-Abujeta JL, Vicario S, García-Endrino A, López-Matas MA, García-Sedeño MD, et al. Goji berries (Lycium barbarum): Risk of allergic reactions in individuals with food allergy. J Investig Allergol Clin Immunol. 2012;22(5):345-50.
  10. Cai H, Liu F, Zuo P, Huang G, Song Z, Wang T, et al. Practical application of antidiabetic efficacy of Lycium barbarum polysaccharide in patients with type 2 diabetes. Med Chem. 2015;11(4):383-90.
  11. Potterat O. Goji (Lycium barbarum and L. chinense): Phytochemistry, pharmacology and safety in the perspective of traditional uses and recent popularity. Planta Med 2010;76(1):7-19.
  12. Guzmán CE, Guzmán-Moreno CG, Assad-Morell JL, Edgar Francisco Carrizales-Sepúlveda EF. Flecainide toxicity associated with the use of goji berries: a case report. Eur Heart J Case Rep. 2021;5(6):ytab204. PubMed
  13. Liu R, Tam TW, Mao J, et al. In vitro activity of Lycium barbarum (Goji) against major human phase I metabolism enzymes. Complement Integr Med. 2016;13(3):257-265.
  14. Zhang J, Tian L, Xie B. Bleeding due to a probable interaction between warfarin and Gouqizi (Lycium Barbarum L.). Toxicol Rep. 2015;2:1209-1212. PubMed

See these in context on the Goji monograph →

Schisandra 26 references
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. Iwata H, Tezuka Y, Kadota S, et al. Identification and characterization of potent CYP3A4 inhibitors in Schisandra fruit extract. Drug Metab Dispos 2004;32:1351-8. PubMed
  3. Mu Y, Zhang J, Zhang S, et al. Traditional Chinese medicines Wu Wei Zi (Schisandra chinensis Baill) and Gan Cao (Glycyrrhiza uralensis Fisch) activate pregnane X receptor and increase warfarin clearance in rats. J Pharmacol Exp Ther 2006;316:1369-77. PubMed
  4. Xin HW, Wu XC, Li Q, et al. Effects of Schisandra sphenanthera extract on the pharmacokinetics of tacrolimus in healthy volunteers. Br J Clin Pharmacol 2007;64:469-75.
  5. Qin XL, Bi HC, Wang XD, et al. Mechanistic understanding of the different effects of Wuhzi Tablet (Schisandra sphenanthera extract) on the absorption and first-pass intestinal and hepatic metabolism of tacrolimus (FK506). Int J Pharm 2010;389:114-21.
  6. Makino, T., Mizuno, F., and Mizukami, H. Does a kampo medicine containing schisandra fruit affect pharmacokinetics of nifedipine like grapefruit juice? Biol.Pharm.Bull. 2006;29(10):2065-2069. PubMed
  7. Fan L, Mao XQ, Tao GY, Wang G, Jiang F, Chen Y, Li Q, Zhang W, Lei HP, Hu DL, Huang YF, Wang D, Zhou HH. Effect of Schisandra chinensis extract and Ginkgo biloba extract on the pharmacokinetics of talinolol in healthy volunteers. Xenobiotica. 2009 Mar;39(
  8. Jiang W, Wang X, Xu X, Kong L. Effect of Schisandra sphenanthera extract on the concentration of tacrolimus in the blood of liver transplant patients. Int J Clin Pharmacol Ther. 2010 Mar;48(3):224-9. PubMed
  9. Xin HW, Wu XC, Li Q, Yu AR, Xiong L. Effects of Schisandra sphenanthera extract on the pharmacokinetics of midazolam in healthy volunteers. Br J Clin Pharmacol. 2009 May;67(5):541-6.
  10. Li J, Chen S, Qin X, et at. Wuzhi Tablet (<i>Schisandra sphenanthera</i> Extract) is a Promising Tacrolimus-Sparing Agent for Renal Transplant Recipients Who are CYP3A5 Expressers: a Two-Phase Prospective Study. Drug Metab Dispos. 2017;45(11):1114-1119.
  11. Qin XL, Li JL, Wang SH, Chen X, Huang M, Bi HC. Co-administration of Wuzhi tablet (Schisandra sphenanthera extract) alters tacrolimus pharmacokinetics in a dose- and time-dependent manner in rats. J Ethnopharmacol. 2020;263:113233. PubMed
  12. Yuan F, Liang X, Chen X, Qin X, Tan C, Wang L. CYP2C19 is involved in the effect of Wuzhi tablet (Schisandra sphenanthera extract) and its constituents on the pharmacokinetics of intravenous voriconazole. Pharmazie. 2020;75(11):559-564. DOI
  13. Zhang Z, Lu X, Dong L, Ma J, Fan X. Clinical observation on the effect of Wuzhi soft capsule on FK506 concentration in membranous nephropathy patients. Medicine (Baltimore). 2019;98(48):e18150. PubMed
  14. Yoo HH, Lee M, Lee MW, Lim SY, Shin J, Kim DH. Effects of Schisandra lignans on P-glycoprotein-mediated drug efflux in human intestinal Caco-2. Planta Med. 2007;73(5):444-50.
  15. Qiangrong P, Wang T, Lu Q, Hu X. Schisandrin B--a novel inhibitor of P-glycoprotein. Biochem Biophys Res Commun. 2005;335(2):406-11. PubMed
  16. Chen L, Ji N, Zhang M, Chen W. The influence of Wuzhi capsule on the pharmacokinetics of cyclophosphamide. Recent Pat Anticancer Drug Discov 2021. PubMed
  17. Cheng X, Ma J, Xu X, Zhang L, Wang X, Wu R. Effect of Wuzhi capsules on cyclosporine A concentration in children with aplastic anemia immunotherapy: a single-center observational study. Expert Rev Clin Pharmacol 2022:1-5. PubMed
  18. Cheng F, Li Q, Wang J, Zeng F, Zhang Y. Effects and safety evaluation of Wuzhi capsules combined with tacrolimus for the treatment of kidney transplantation recipients. J Clin Pharm Ther 2021;46(6):1636-49. PubMed
  19. Teng F, Wang W, Zhang W, et al. Effect of hepar-protecting Wuzhi capsule on pharmacokinetics and dose-effect character of tacrolimus in healthy volunteers. Biopharm Drug Dispos 2022.
  20. Kou K, Sun X, Li M, et al. Beneficial effects of Wuzhi capsule on tacrolimus blood concentrations in liver transplant patients with different donor-recipient CYP3A5 genotypes. J Clin Pharm Ther 2022;47(2):200-10. PubMed
  21. Peng Y, Jiang F, Zhou R, et al. Clinical evaluation of the efficacy and safety of co-administration of Wuzhi capsule and tacrolimus in adult Chinese patients with myasthenia gravis. Neuropsychiatr Dis Treat 2021;17:2281-9. PubMed
  22. Chen P, Dai R, She Y, et al. Prediction of tacrolimus and Wuzhi tablet pharmacokinetic interaction magnitude in renal transplant recipients. Clin Transplant 2022;36(12):e14807. PubMed
  23. Qu J, Bian R, Liu B, et al. The pharmacokinetic study of tacrolimus and Wuzhi capsule in Chinese liver transplant patients. Front Pharmacol 2022;13:956166. PubMed
  24. Zhou Y, Huang X, Liu L, et al. Effect of Wuzhi preparations on tacrolimus in CYP3A5 expressers during the early period after transplantation: A real-life experience from heart transplant recipients. Transpl Immunol 2023;76:101748. PubMed
  25. Huang Q, Lin X, Wang Y, et al. Tacrolimus pharmacokinetics in pediatric nephrotic syndrome: A combination of population pharmacokinetic modelling and machine learning approaches to improve individual prediction. Front Pharmacol 2022;13:942129. PubMed
  26. Wang CB, Zhang YJ, Zhao MM, Zhao LM. Population pharmacokinetic analyses of tacrolimus in non-transplant patients: a systematic review. Eur J Clin Pharmacol 2023;79(7):897-913. PubMed

See these in context on the Schisandra monograph →

Ba Ji Tian 2 references
  1. Soon, Y. Y. and Tan, B. K. Evaluation of the hypoglycemic and anti-oxidant activities of Morinda officinalis in streptozotocin-induced diabetic rats. Singapore Med J 2002;43(2):077-085.
  2. Du Y, Zheng Q, Ou ZH, et al. Efficacy and safety of Morinda officinalis oligosaccharide capsules for depressive disorder: a systematic review and meta-analysis. Braz J Psychiatry 2021;43(3):306-313. PubMed

See these in context on the Ba Ji Tian monograph →

American Dogwood 1 reference
  1. Dietary Supplements: What You Need to Know — NIH Office of Dietary Supplements Source

See these in context on the American Dogwood monograph →

Rehmannia 3 references
  1. Zhang R, Zhou J, Jia Z, et al. Hypoglycemic effect of Rehmannia glutinosa oligosaccharide in hyperglycemic and alloxan-induced diabetic rats and its mechanism. J Ethnopharmacol 2004;90:39-43. PubMed
  2. Zhang RX, Li MX, Jia ZP. Rehmannia glutinosa: review of botany, chemistry and pharmacology. J Ethnopharmacol 2008;117(2):199-214. PubMed
  3. Chao CH, Hsu JL, Chen MF, et al. Anti-hypertensive effects of Radix Rehmanniae and its active ingredients. Nat Prod Res. 2020;34(11):1547-1552.

See these in context on the Rehmannia monograph →

Poria Mushroom 3 references
  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Kim H, Park I, Park K, Park S, Kim YI, Park BG. The positive effects of Poria cocos extract on quality of sleep in insomnia rat models. Int J Environ Res Public Health 2022;19(11):6629. PubMed
  3. Lv Q, Di X, Bian B, Li K, Guo J. Neuroprotective effects of Poria cocos (Agaricomycetes) essential oil on Aß1-40-induced learning and memory deficit in rats. Int J Med Mushrooms 2022;24(10):73-82.

See these in context on the Poria Mushroom monograph →

Fennel 17 references
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Zhu M, Wong PY, Li RC. Effect of oral administration of fennel (Foeniculum vulgare) on ciprofloxacin absorption and disposition in the rat. J Pharm Pharmacol 1999;51:1391-6.
  4. Gral N, Beani JC, Bonnot D, et al. [Plasma levels of psoralens after celery ingestion]. Ann Dermatol Venereol 1993;120:599-603.
  5. Burkhard PR, Burkhardt K, Haenggeli CA, Landis T. Plant-induced seizures: reappearance of an old problem. J Neurol 1999;246:667-70. PubMed
  6. Rosti L, Nardini A, Bettinelli ME, Rosti D. Toxic effects of a herbal tea mixture in two newborns. Acta Paediatrica 1994;83:683. PubMed
  7. Cuzzolin L, Zaffani S, and Benoni G. Safety implications regarding use of phytomedicines. Eur.J Clin Pharmacol. 2006;62:37-42. PubMed
  8. Tognolini, M., Ballabeni, V., Bertoni, S., Bruni, R., Impicciatore, M., and Barocelli, E. Protective effect of Foeniculum vulgare essential oil and anethole in an experimental model of thrombosis. Pharmacol.Res 2007;56(3):254-260. PubMed
  9. Subehan, Usia, T., Iwata, H., Kadota, S., and Tezuka, Y. Mechanism-based inhibition of CYP3A4 and CYP2D6 by Indonesian medicinal plants. J Ethnopharmacol. 5-24-2006;105(3):449-455. PubMed
  10. Tognolini, M., Barocelli, E., Ballabeni, V., Bruni, R., Bianchi, A., Chiavarini, M., and Impicciatore, M. Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. Life Sci. 2-23-2006;78(13):1419-1432. PubMed
  11. Subehan, Zaidi, S. F., Kadota, S., and Tezuka, Y. Inhibition on human liver cytochrome P450 3A4 by constituents of fennel (Foeniculum vulgare): identification and characterization of a mechanism-based inactivator. J Agric.Food Chem. 12-12-2007;55(25):101 PubMed
  12. LEVY, S. B. Bronchial asthma due to ingestion of fennel and fennel seed. Ann.Allergy 1948;6(4):415.
  13. Ottolenghi, A., De Chiara, A., Arrigoni, S., Terracciano, L., and De Amici, M. [Diagnosis of food allergy caused by fruit and vegetables in children with atopic dermatitis]. Pediatr Med Chir 1995;17(6):525-530.
  14. Trabace L, Tucci P, Ciuffreda L, et al. "Natural" relief of pregnancy-related symptoms and neonatal outcomes: above all do no harm. J Ethnopharmacol. 2015;174:396-402. PubMed
  15. Denaxa D, Arkwright PD. Fennel as a cause of immediate hypersensitivity to toothpaste. Ann Allergy Asthma Immunol. 2020;125(1):99-100. PubMed
  16. Lee HW, Ang L, Lee MS, Alimoradi Z, Kim E. Fennel for reducing pain in primary dysmenorrhea: a systematic review and meta-analysis of randomized controlled trials. Nutrients 2020;12(11):3438. PubMed
  17. Mathew T, John SK, Javali M, Vasireddy M, Nadig R, Sarma GRK. Substance use related cluster headache: A case series. Headache 2022;62(7):908-910. PubMed

See these in context on the Fennel monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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