Interactions on record — worth a quick check against your medications. Based on 4 of 5 ingredients. Check your meds →
Dietary supplement

Hard Ingredients & Drug Interactions

by Core Nutritionals

Hard label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Hard 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: Moderate

Hard is a dietary supplement by Core Nutritionals with 5 active ingredients. Its ingredients are commonly taken for anxiety and stress, relaxation and calm, sleep support.Based on those ingredients, 1,476 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are KSM-66 full-spectrum Ashwagandha root extract, L-Theanine, 3,3'-Diindolylmethane. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Hard by Core Nutritionals

Ask about any prescription or over-the-counter medication and we check it for interactions with Hard by Core Nutritionals — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Hard by Core Nutritionals

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 Aug 6, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 5 of its 5 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Hard contains 5 active ingredients: L-theanine, 3,3'-diindolylmethane, N-coumaroyldopamine, KSM-66 full-spectrum ashwagandha root extract, and phosphatidyl serine. L-theanine is an amino acid; diindolylmethane is a plant compound from cruciferous vegetables; ashwagandha is an herbal extract; and phosphatidyl serine is a fat-based compound found in cell membranes.

The product also contains inactive ingredients—brown rice flour, magnesium stearate, and hypromellose (a capsule material)—that serve as fillers and binders.

Does it work?

Moderate evidence
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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: reduce cortisol and support body recomposition.
  • We looked for evidence on: Stress, Anxiety, Generalized anxiety disorder (GAD), Athletic performance, Exercise-induced muscle soreness, Psychological well-being — and 3 related terms.
  • The strongest evidence on file: Ashwagandha is rated "Possibly Effective" for Anxiety (Natural Medicines).
  • Also on file: Ashwagandha is rated "Possibly Effective" for Generalized anxiety disorder (GAD), Stress.
  • Also on file: Ashwagandha is rated "Insufficient Reliable Evidence To Rate" for Athletic performance, Psychological well-being.

Ashwagandha and phosphatidyl serine have the clearest evidence. Ashwagandha is rated possibly effective for insomnia, anxiety, stress, and generalized anxiety disorder.

Phosphatidyl serine is rated possibly effective for age-related cognitive decline and Alzheimer's disease. For other uses, the evidence is insufficient: L-theanine's value for cognitive function is possibly effective, but its role in age-related decline, Alzheimer's, anxiety, and OCD isn't established.

Diindolylmethane lacks reliable evidence for benign prostatic hyperplasia, breast cancer, and other cancers it's marketed for. Phosphatidyl serine also lacks sufficient evidence for ADHD, athletic performance, or general cognitive function.

The evidence, ingredient by ingredient Theanine Diindolylmethane Ashwagandha Phosphatidylserine

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 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

L-theanine and diindolylmethane are generally well tolerated short-term, but long-term safety is not well studied for either. Common side effects of L-theanine include headaches and drowsiness; diindolylmethane may cause diarrhea, gas, headache, nausea, rash, or vomiting.

Ashwagandha is generally well tolerated short-term, though diarrhea, nausea, and gastrointestinal upset can occur, and rare cases of liver damage have been reported. Phosphatidyl serine is also generally well tolerated; common side effects include headache, insomnia (especially at higher doses), nausea, and gas.

For pregnancy: L-theanine and diindolylmethane lack safety data and should be avoided during pregnancy; ashwagandha is rated likely unsafe due to a traditional concern about miscarriage; phosphatidyl serine also lacks sufficient data and should be avoided. For breastfeeding: L-theanine, diindolylmethane, ashwagandha, and phosphatidyl serine all lack enough safety information—breastfeeding while taking any of these has not been adequately studied.

Side effects, ingredient by ingredient Theanine Diindolylmethane Ashwagandha Phosphatidylserine

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 4 of the 4 matched ingredients can interact with medications — Ashwagandha, Phosphatidylserine, Diindolylmethane, Theanine.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: immunosuppressants / transplant drugs; diabetes medications.
  • For scale: 1,477 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.

Check these medication types before using Hard: blood pressure medications (antihypertensive drugs), as both L-theanine and ashwagandha may lower blood pressure further; sedatives, benzodiazepines, and other central nervous system depressants (the product may enhance drowsiness); antidiabetes drugs, since ashwagandha may lower blood sugar; thyroid hormones, as ashwagandha may amplify their effects; estrogen-based medications, since diindolylmethane may interfere with them; and any liver-toxic drugs, given ashwagandha's rare association with liver damage. Also check with your pharmacist if you take immunosuppressants, cholinergic or anticholinergic drugs, or diuretics.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Hard is designed primarily for stress, anxiety, and cognitive support, with the strongest evidence behind ashwagandha and phosphatidyl serine for those uses. Because this product interacts with many medication categories—especially blood pressure drugs, sedatives, diabetes medications, thyroid hormones, and immunosuppressants—you should check your prescriptions against the interaction details on this page before starting.

If you're pregnant, breastfeeding, or taking any regular medications, talk with your doctor or pharmacist first.

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

Assessment coverage: 4 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 23, 2017.

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 Hard, straight from the product label.

Brand Core Nutritionals
Barcode (UPC) 8570757001535
Net contents 84 Capsule(s)
Market status On market
Date entered into DSLD Jun 23, 2017
DSLD ID 74101
Product type Other Combinations
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 Hard by Core Nutritionals, 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
28
UPC/BARCODE
8570757001535
IngredientAmount% DV
L-Theanine300 mg--
3,3'-Diindolylmethane200 mg--
N-Coumaroyldopamine40 mg--
KSM-66 full-spectrum Ashwagandha root extract600 mg--
Phosphatidyl Serine500 mg--

Other ingredients: Brown Rice Flour, Magnesium Stearate, Hypromellose

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.
General Statements

Core HARD redefines recomposition with an advanced and synergistic blend of highly effective ingredients. Key ingredients in Core HARD were shown to: Reduce measurements of cortisol by 27% in clinical trial in humans. Help balance the enzymes involved in estrogen metabolism. Increase performance and reduce perception of stress in healthy athletes.

Advanced recomposition and hardening agent

4 week supply

Vegetable caps

Manufactured in a U.S. cGMP Facility.

Precautions

Warning: This product is only intended for use in healthy adults in 18 years of age or older.

Pregnant or nursing women should not use this product. Consult your healthcare provider before using this product, especially if you are taking any prescription, over the counter medication, dietary supplement product, or if you have any pre-existing medical condition including but not limited to: high or low blood pressure, cardiac arrhythmia, stroke, heart, liver, kidney or thyroid disease, seizure disorder, psychiatric disease, diabetes, difficulty urinating due to prostate enlargement or if you are taking a MAOI (Monoamine Oxidase Inhibitor) or any other medication.

Consult your healthcare provider before using this product, especially if you are taking any prescription, over the counter medication, dietary supplement product, or if you have any pre-existing medical condition including but not limited to: high or low blood pressure, cardiac arrhythmia, stroke, heart, liver, kidney or thyroid disease, seizure disorder, psychiatric disease, diabetes, difficulty urinating due to prostate enlargement or if you are taking a MAOI (Monoamine Oxidase Inhibitor) or any other medication. Discontinue use and consult your health care professional if you experience adverse reaction to this product. Discontinue use 2 weeks prior to surgery. Do not exceed recommended serving. Do not use if safety seal is broken or missing.

Keep out of reach of children.

Allergen information: contains milk.

Suggested/Recommended/Usage/Directions

Directions: Take 1 capsule 2-3 times per day. For optimal results, take 1 capsule upon waking, 1 capsule midday, and 1 capsule before bed. Do not exceed 4 capsules in a 24 hour period. For best results, use for 4 to 8 weeks. Do not use longer than 8 continuous weeks without taking a 4 week break.

FDA Disclaimer Statement

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

Formulation

No artificial colors Gluten free

FDA Statement of Identity

Dietary Supplement

Formula

Allergen information: contains milk.

Brand IP Statement(s)

KSM66 is a registered trademark of Ixoreal Biomed Inc.

KSM-66 ashwagandha

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See for yourself

Hard by Core Nutritionals label

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

Hard 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 Hard by Core Nutritionals

These are the 5 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container28 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.

L-Theanine

Interacts with
565 drugs
300 mg per serving

Theanine (usually L-theanine) is an amino acid found naturally in tea leaves that many people take to feel calmer and less stressed without strong dro...

L-Theanine monograph & interactions

3,3'-Diindolylmethane

Interacts with
269 drugs
200 mg per serving

Diindolylmethane (DIM) is a compound made when your body digests cruciferous vegetables, and it is sold as a supplement mainly for hormone balance and...

3,3'-Diindolylmethane monograph & interactions

N-Coumaroyldopamine

40 mg per serving

KSM-66 full-spectrum Ashwagandha root extract

Interacts with
1,372 drugs
600 mg per serving Form: Withanolides

Ashwagandha is an Ayurvedic herb most often taken to help with stress, anxiety, and sleep, and some small studies suggest it may help, though the evid...

KSM-66 full-spectrum Ashwagandha root extract monograph & interactions

Phosphatidyl Serine

Interacts with
219 drugs
500 mg per serving

Phosphatidylserine is a natural fat-like compound found in cell membranes, especially in the brain, and it is sold mainly to support memory and thinki...

Phosphatidyl Serine monograph & interactions

Other (inactive) ingredients: Brown Rice Flour, Magnesium Stearate, Hypromellose. These complete the product’s ingredient list but are not active constituents.

Interaction report

Hard by Core Nutritionals Drug Interactions

Want to check YOUR meds against Hard?

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
1,476Drugs
1,094 Moderate 382 Minor

Ingredients driving the most interactions

KSM-66 full-spectrum Ashwagandha root extract 1,372
L-Theanine 565
3,3'-Diindolylmethane 269
Phosphatidyl Serine 219

Individual Drug Interactions

The ingredients in Hard interact with 1,476 drugs. Click any drug to see the details.

4 of the 5 ingredients in Hard interact with drugs. Each result below shows which ingredient is responsible. KSM-66 full-spectrum Ashwagandha root extract L-Theanine 3,3'-Diindolylmethane Phosphatidyl Serine

Each ingredient & the kinds of drugs it affects

For each ingredient in Hard 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.

KSM-66 full-spectrum Ashwagandha root extract10 drug types · 1,372 drugs

Antidiabetes Drugs

Theoretically, taking ashwagandha with antidiabetes drugs might increase the risk of hypoglycemia.
There is preliminary clinical evidence suggesting that ashwagandha might lower blood glucose levels. Theoretically, ashwagandha might have additive effects when used with antidiabetes drugs and increase the risk of hypoglycemia.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, taking ashwagandha with antihypertensive drugs might increase the risk of hypotension.
Animal research suggests that ashwagandha might lower systolic and diastolic blood pressure. Theoretically, ashwagandha might have additive effects when used with antihypertensive drugs and increase the risk of hypotension.

Likelihood Possible Evidence D
Benzodiazepines

Theoretically, taking ashwagandha might increase the sedative effects of benzodiazepines.
There is preliminary evidence that ashwagandha might have an additive effect with diazepam (Valium) and clonazepam (Klonopin). This may also occur with other benzodiazepines.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, taking ashwagandha might increase the sedative effects of CNS depressants.
Ashwagandha seems to have sedative effects. Theoretically, this may potentiate the effects of barbiturates, other sedatives, and anxiolytics.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, taking ashwagandha with hepatotoxic drugs might increase the risk of liver damage.
Ashwagandha has been linked to cases of acute hepatitis, liver failure, hepatic encephalopathy, autoimmune hepatitis, the need for liver transplantation, and death due to liver failure.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, taking ashwagandha might decrease the effects of immunosuppressants.
Ashwagandha has demonstrated immunostimulant effects in humans. Animal research has shown that ashwagandha can attenuate the immunosuppression caused by cyclophosphamide.

Likelihood Possible Evidence D
Thyroid Hormone

Ashwagandha might increase the effects and adverse effects of thyroid hormone.
Concomitant use of ashwagandha with thyroid hormones may cause additive therapeutic and adverse effects. Preliminary clinical research and animal studies suggest that ashwagandha boosts thyroid hormone synthesis and secretion. In one clinical study, ashwagandha increased triiodothyronine (T3) and thyroxine (T4) levels by 41.5% and 19.6%, respectively, and reduced serum TSH levels by 17.4% from baseline in adults with subclinical hypothyroidism.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, ashwagandha might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that ashwagandha extract induces CYP1A2 enzymes.

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

Theoretically, ashwagandha might decrease the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that ashwagandha extract induces CYP3A4 enzymes.

Likelihood Possible Evidence D
Serotonergic Drugs

Some animal studies have reported that ashwagandha can enhance serotonergic transmission by altering certain serotonin (5-HT) receptors. However, there is no evidence to suggest that ashwagandha increases the risk of serotonin-related effects, and there have been no published case reports of serotonin syndrome when combined with other serotonergic drugs. Nevertheless, due to the lack of extensive studies on the matter and the fact that ashwagandha appears to affect serotonergic pathways, it would be prudent to exercise caution when combining it with drugs that affect serotonin. [References: - Effects of Withania somnifera (Ashwaga ndha) on Stress and the Stress-Related Neuropsychiatric Disorders Anxiety, Depression, and Insomnia. Curr Neuropharmacol. 2021 Sep 14; 19: 1468–1495. - A Prospective, Randomized Double-Blind, Placebo-Controlled Study of Safety and Efficacy of a High-Concentration Full-Spectrum Extract of Ashwagandha Root in Reducing Stress and Anxiety in Adults. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3573577/]

Likelihood Possible Evidence C
KSM-66 full-spectrum Ashwagandha root extract full monograph & interactions

L-Theanine3 drug types · 565 drugs

Antihypertensive Drugs

Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Animal research shows that theanine can lower blood pressure in spontaneously hypertensive animals. Theoretically, concomitant use of theanine and antihypertensive drugs might potentiate the antihypertensive activity.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, theanine might have additive sedative effects when used in conjunction with CNS depressants. However, it is unclear if this concern is clinically relevant.
Theoretically, theanine may compete with glutamate and/or increase plasma gamma-aminobutyric acid (GABA) levels, which could cause CNS depression. In one clinical study, some subjects taking oral theanine reported drowsiness.

Likelihood Unlikely Evidence D
Serotonergic Drugs

Clinical studies regarding the effects of L-theanine on serotonin levels are conflicting. Some studies suggest it can increase serotonin levels in the brain while others report that it may decrease them. Nevertheless, there have been no reports of l-theanine being a causative agent in serotonergic-related side effects or serotonin syndrome.

Likelihood Unlikely Evidence C
L-Theanine full monograph & interactions

3,3'-Diindolylmethane3 drug types · 269 drugs

Diuretic Drugs

Theoretically, diindolylmethane might increase the risk of hyponatremia if used with sodium-depleting diuretics.
Large doses of diindolylmethane (600 mg daily) have been associated with two cases of asymptomatic hyponatremia in clinical research.

Likelihood Possible Evidence B
Estrogens

Theoretically, diindolylmethane might increase or decrease the effects of estrogens.
Diindolylmethane might have mild estrogenic or antiestrogenic effects. Theoretically, large amounts of diindolylmethane might interfere with hormone replacement therapy.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, diindolylmethane might lower serum levels of CYP1A2 substrates.
In vitro evidence suggests that diindolylmethane can induce CYP1A2. Theoretically, it might increase metabolism of CYP1A2 substrates and lower serum concentrations. This interaction has not been reported in humans.

Likelihood Unlikely Evidence D
3,3'-Diindolylmethane full monograph & interactions

Phosphatidyl Serine2 drug types · 219 drugs

Anticholinergic Drugs

Theoretically, phosphatidylserine might decrease the effectiveness anticholinergic drugs.
Phosphatidylserine is thought to increase acetylcholine levels, which could theoretically interfere with the activity of anticholinergic agents.

Likelihood Possible Evidence B
Cholinergic Drugs

Theoretically, phosphatidylserine might have additive effects with cholinergic drugs.
Phosphatidylserine is thought to increase acetylcholine levels, which could theoretically lead to additive cholinergic effects when used with cholinergic drugs.

Likelihood Possible Evidence B
Phosphatidyl Serine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Hard, from the product label.

Core Nutritionals

See all Core Nutritionals products
Name
Core Nutritionals, LLC
City
Arlington
State
Virginia
ZipCode
22203
Phone Number
(888) 978-2332
Web Address
www.CoreNutritionals.com
Pharmacist Counseling Corner

Hard by Core Nutritionals: Common Questions

Does Hard by Core Nutritionals interact with any medications?
Yes. Based on its ingredients, Hard has a known interaction with 1,476 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Hard contains 5 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 it safe to take Hard while I'm pregnant or breastfeeding?
No—there isn't enough safety data for any of the ingredients during pregnancy or breastfeeding. L-theanine, diindolylmethane, and phosphatidyl serine all lack sufficient information; ashwagandha is rated likely unsafe in pregnancy due to a traditional concern about miscarriage risk. Talk with your doctor or pharmacist about whether this product is right for you.
What is ashwagandha and what is it supposed to do?
Ashwagandha is an herbal extract from an Ayurvedic plant. In Hard, it's included as KSM-66 full-spectrum ashwagandha root extract. It's rated possibly effective for insomnia, anxiety, stress, and generalized anxiety disorder, though the evidence for other uses in the product is not established.
Does this product have any side effects?
The ingredients are generally well tolerated, but side effects are possible. L-theanine may cause headaches or drowsiness; diindolylmethane and ashwagandha may cause nausea, diarrhea, or gas; and phosphatidyl serine may cause headaches, insomnia, or nausea. Rare serious effects like liver damage have been linked to ashwagandha, though these are uncommon.
What does phosphatidyl serine do?
Phosphatidyl serine is a fat compound in cell membranes. It's rated possibly effective for age-related cognitive decline and Alzheimer's disease, but evidence for other cognitive uses is insufficient.
Will this product actually help my memory or focus?
L-theanine is rated possibly effective for cognitive function; phosphatidyl serine is rated possibly effective for age-related decline and Alzheimer's; but neither has strong evidence for general focus or memory in healthy adults. Diindolylmethane and ashwagandha lack reliable evidence for cognitive effects.
What's in the capsule besides the active ingredients?
The capsule contains three inactive ingredients: brown rice flour, magnesium stearate, and hypromellose (a capsule material used as a binder and filler).

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.

Hard label
Go deeper

The Full Monographs Behind Hard’s Ingredients

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

Herb & supplement monograph

Theanine

Interacts with 565 drugs

Theanine (usually L-theanine) is an amino acid found naturally in tea leaves that many people take to feel calmer and less stressed without strong drowsiness. Early research suggests it may...

Read the full Theanine monograph → Herb & supplement monograph

Diindolylmethane

Interacts with 269 drugs

Diindolylmethane (DIM) is a compound made when your body digests cruciferous vegetables, and it is sold as a supplement mainly for hormone balance and cancer prevention. Although early lab s...

Read the full Diindolylmethane monograph → Herb & supplement monograph

Ashwagandha

Interacts with 1,372 drugs

Ashwagandha is an Ayurvedic herb most often taken to help with stress, anxiety, and sleep, and some small studies suggest it may help, though the evidence is still limited. It is generally w...

Read the full Ashwagandha monograph → Herb & supplement monograph

Phosphatidylserine

Interacts with 219 drugs

Phosphatidylserine is a natural fat-like compound found in cell membranes, especially in the brain, and it is sold mainly to support memory and thinking. Some research suggests possible bene...

Read the full Phosphatidylserine monograph →
Sources

Sources & How We Checked

Hard'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 61 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.

Theanine 6 references
  1. Yokogoshi H, Kobayashi M. Hypotensive effect of gamma-glutamylethylamide in spontaneously hypertensive rats. Life Sci 1998;62:1065-8.
  2. Haskell, C. F., Kennedy, D. O., Milne, A. L., Wesnes, K. A., and Scholey, A. B. The effects of L-theanine, caffeine and their combination on cognition and mood. Biol.Psychol. 2008;77(2):113-122. PubMed
  3. Yokogoshi, H., Kato, Y., Sagesaka, Y. M., Takihara-Matsuura, T., Kakuda, T., and Takeuchi, N. Reduction effect of theanine on blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats. Biosci.Biotechnol.Biochem. 1995;59(4):615-618. PubMed
  4. Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011;16(4):348-
  5. Hidese S, Ota M, Wakabayashi C, et al. Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr 2017;29(2):72-9.
  6. Tsuchiya T, Honda H, Oikawa M, et al. Oral administration of the amino acids cystine and theanine attenuates the adverse events of S-1 adjuvant chemotherapy in gastrointestinal cancer patients. Int J Clin Oncol 2016;21(6):1085-90. PubMed

See these in context on the Theanine monograph →

Diindolylmethane 14 references
  1. Natl Inst Health, Natl Inst Environmental Health Sci. Indole-3-carbinol. Available at: http://ntp-server.niehs.nih.gov.
  2. Balk JL. Indole-3-carbinol for cancer prevention. Altern Med Alert 2000; 3:105-7.
  3. Riby JE, Chang GHF, Firestone GL, Bjeldanes LF. Ligand-independent activation of estrogen receptor function by 3,3'-diindolylmethane in human breast cancer cells. Biochem Pharmacol 2000;60:167-77. PubMed
  4. Lake BG, Tredger JM, Renwick AB, et al. 3'3-diindolylmethane induces CYP1A2 in cultured precision-cut human liver slices. Xenobiotica 1998;28:803-11. PubMed
  5. Dalessandri, K. M., Firestone, G. L., Fitch, M. D., Bradlow, H. L., and Bjeldanes, L. F. Pilot study: effect of 3,3'-diindolylmethane supplements on urinary hormone metabolites in postmenopausal women with a history of early-stage breast cancer. Nutr Canc PubMed
  6. Reed, G. A., Arneson, D. W., Putnam, W. C., Smith, H. J., Gray, J. C., Sullivan, D. K., Mayo, M. S., Crowell, J. A., and Hurwitz, A. Single-dose and multiple-dose administration of indole-3-carbinol to women: pharmacokinetics based on 3,3'-diindolylmetha
  7. Reed, G. A., Sunega, J. M., Sullivan, D. K., Gray, J. C., Mayo, M. S., Crowell, J. A., and Hurwitz, A. Single-dose pharmacokinetics and tolerability of absorption-enhanced 3,3'-diindolylmethane in healthy subjects. Cancer Epidemiol.Biomarkers Prev. 2008; PubMed
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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.

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