Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Alpha Testosterone Ingredients & Drug Interactions

by Shredz

Alpha Testosterone label
See full label image
Capsule Category: Botanical With Nutrients
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Alpha Testosterone 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

Alpha Testosterone is a dietary supplement by Shredz with 6 active ingredients. Its ingredients are commonly taken for zinc deficiency, immune support, cold symptoms.Based on those ingredients, 739 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Fenugreek, Eurycoma, Velvet Bean 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 Alpha Testosterone by Shredz

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

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HelloPharmacist Scorecard of Alpha Testosterone by Shredz

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 12, 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 1 of its 6 active ingredients.
  • “SHREDZ(R) Proprietary Blend” is a proprietary blend — the label gives one combined amount (1,915 mg) without saying how much of each component you get.

Alpha Testosterone contains six ingredients, four of which we have data for: zinc (a mineral), maca (a plant root), anacyclus pyrethrum (an herbal extract), eurycoma longifolia (also called tongkat ali), fenugreek (a seed), and velvet bean extract — which contains levodopa, a compound similar to a pharmaceutical drug. The product also includes a proprietary blend, meaning some ingredients are grouped together and their individual amounts aren't disclosed.

The remaining contents are inactive ingredients — gelatin, rice flour, magnesium stearate, titanium dioxide, and food colorings.

Does it work?

Strong 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

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Zinc deficiency — rated "Effective" (Zinc) (Natural Medicines).
  • On file: Wilson disease — rated "Likely Effective" (Zinc) (Natural Medicines).
  • On file: Acne — rated "Possibly Effective" (Zinc) (Natural Medicines).
  • On file: Acrodermatitis enteropathica — rated "Possibly Effective" (Zinc) (Natural Medicines).
  • On file: Age-related macular degeneration (AMD) — rated "Possibly Effective" (Zinc) (Natural Medicines).

The evidence for this product's ingredients is mixed and incomplete. Zinc is effective for zinc deficiency and likely effective for Wilson disease (a copper-storage disorder); for acne, macular degeneration, and diabetes, the evidence is only possibly effective.

Fenugreek shows possibly effective evidence for sexual dysfunction, sexual arousal, menstrual cramps, and diabetes. Eurycoma is possibly effective for sexual desire but possibly ineffective for athletic performance.

Maca, anacyclus pyrethrum, and velvet bean extract lack sufficient reliable evidence to rate — the data we hold shows their effectiveness is unestablished for the claims made about them.

The evidence, ingredient by ingredient Zinc Maca Pellitory Eurycoma Longifolia Fenugreek Cowhage

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 6 of the 6 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 6 of 6.
  • General safety write-ups exist for 6 of 6.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Zinc is well tolerated in oral doses below 40 mg daily for adults, though side effects at higher doses include nausea, vomiting, abdominal cramps, diarrhea, and a metallic taste. Long-term high-dose zinc raises theoretical risk of copper deficiency, which can lead to anemia and low white blood cells.

Fenugreek is generally well tolerated but can cause abdominal pain, bloating, diarrhea, and in rare cases severe allergic reactions including shock. Velvet bean extract contains an active compound (levodopa) and carries caution; it may cause diarrhea, flatulence, and in clinical studies, insomnia in about 3% of users at high doses.

Maca supplement safety hasn't been studied long term, and raw maca can cause stomach pain. Anacyclus pyrethrum has limited safety data and may cause mouth or skin irritation.

All ingredients except zinc carry insufficient or no long-term safety data.

Side effects, ingredient by ingredient Zinc Maca Pellitory Eurycoma Longifolia Fenugreek Cowhage

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?
  • 4 of the 6 matched ingredients can interact with medications — Fenugreek, Zinc, Cowhage, Eurycoma Longifolia.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; Parkinson's medications.
  • For scale: 739 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 your medications against this list before taking this product. Major concerns: If you take MAOIs (an older antidepressant class), methyldopa (a blood pressure drug), or levodopa (a Parkinson's medication), do not use this product due to serious blood pressure spikes.

Moderate concerns: blood thinners (warfarin, clopidogrel), all diabetes drugs, beta-blockers (propranolol, metoprolol), antibiotics (quinolones, tetracyclines, cephalexin), theophylline (asthma), sildenafil (Viagra), tricyclic antidepressants, guanethidine, antipsychotics, and HIV medications (ritonavir, integrase inhibitors). Use the medication checker on this page to verify your exact drugs.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with strong clinical evidence behind its ingredients' uses. Major medication interactions have been identified, and safety information is well characterized.

This product is aimed at testosterone support, but the evidence for most ingredients is weak or unproven. If you take any prescription medications — especially blood thinners, antidiabetes drugs, blood pressure meds, antidepressants (especially MAOIs), antibiotics, or HIV drugs — talk to your pharmacist before starting.

Velvet bean extract's levodopa content makes it risky with certain older blood pressure or psychiatric medications.

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

Assessment coverage: 6 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Apr 25, 2014.

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 Alpha Testosterone, straight from the product label.

Brand Shredz
Barcode (UPC) 811207021398
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Apr 25, 2014
DSLD ID 32027
Product type Botanical With Nutrients
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 Alpha Testosterone by Shredz, 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
30
UPC/BARCODE
811207021398
IngredientAmount% DV
Zinc29.6 mg200%
Maca0 NP--
SHREDZ(R) Proprietary Blend1915 mg--
Anacyclus Pyrethrum0 NP--
Eurycoma0 NP--
Fenugreek0 NP--
Velvet Bean extract0 NP--

Other ingredients: Gelatin, Rice Flour, Magnesium Stearate, Titanium Dioxide, FD&C Red #40, FD&C Blue#1

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.
Precautions

Not for use by persons under age 18.

Do not use if pregnant or nursing.

KEEP OUT OF REACH OF CHILDREN.

Do not use for more than 8 weeks.

WARNING: NEVER EXCEED RECOMMENDED DOSAGE

Do not consume synephrine or caffeine from other sources, including but not limited to, coffee, tea, soda and other dietary supplements or medications containing phenylephrine or caffeine.

Consult you physician prior to use if you are taking medication,including but not limited to, MAOI inhibitors, antidepressants, aspirin, non-steroidal anti-inflammatory drugs or products containing phenylephrine, ephedrine, pseudoephedrine, or other stimulants.

Consult your physician prior to use if you have a medical condition, including but not limited to, heart, liver, kidney, or thyroid disease, psychiatric disorders, difficulty urinating, diabetes, high blood pressure, cardiac arrhythmia, recurrent headaches, enlarged prostate or glaucoma. Discontinue 2 weeks prior to surgery or if you experience rapid heart beat, dizziness, severe headaches or shortness of breath.

Seals/Symbols

MADE IN THE USA

Beyond GENETICS SUPPLEMENTS

INSPECTED GOOD MANUFACTURING PRACTICES cGMP FACILITY

FDA Disclaimer Statement

THIS PRODUCT HAS NOT BEEN EVALUATED BY THE FOOD AND DRUG ADMINISTRATION.THIS PRODUCT IS NOT INTENDED TO DIAGNOSE, TREAT, CURE OR PREVENT ANY DISEASE.

Formula

Contains caffeine.

General Statements

As individuals vary so may results from using this product. This product contains ingredients of international & domestic origin.

FDA Statement of Identity

DIETARY SUPPLEMENTS

Suggested/Recommended/Usage/Directions

Directions: Take two (2) capsules in the morning followed by one (1) capsule in the afternoon.

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

See for yourself

Alpha Testosterone by Shredz label

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

Alpha Testosterone 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 Alpha Testosterone by Shredz

These are the 6 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container30 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.

Zinc

Interacts with
67 drugs
29.6 mg per serving

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but suppleme...

Zinc monograph & interactions

SHREDZ(R) Proprietary Blend

1915 mg per serving

Other (inactive) ingredients: Gelatin, Rice Flour, Magnesium Stearate, Titanium Dioxide, FD&C Red #40, FD&C Blue#1. These complete the product’s ingredient list but are not active constituents.

Interaction report

Alpha Testosterone by Shredz Drug Interactions

Want to check YOUR meds against Alpha Testosterone?

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
739Drugs
17 Major 379 Moderate 343 Minor

Ingredients driving the most interactions

Fenugreek 389
Eurycoma 248
Velvet Bean extract 193
Zinc 67

Individual Drug Interactions

The ingredients in Alpha Testosterone interact with 739 drugs. Click any drug to see the details.

4 of the 6 ingredients in Alpha Testosterone interact with drugs. Each result below shows which ingredient is responsible. Fenugreek Eurycoma Velvet Bean extract Zinc

Each ingredient & the kinds of drugs it affects

For each ingredient in Alpha Testosterone 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.

Fenugreek9 drug types · 389 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, fenugreek might have additive effects when used with anticoagulant or antiplatelet drugs.
Some of the constituents in fenugreek have antiplatelet effects in animal and in vitro research. However, common fenugreek products might not contain sufficient concentrations of these constituents for clinical effects. A clinical study in patients with coronary artery disease or diabetes shows that taking fenugreek seed powder 2.5 grams twice daily for 3 months does not affect platelet aggregation, fibrinolytic activity, or fibrinogen levels .

Likelihood Unlikely Evidence B
Antidiabetes Drugs

Theoretically, fenugreek seed might have additive hypoglycemic effects when used with antidiabetes drugs.
Clinical research shows that fenugreek seed can reduce fasting blood glucose and 2-hour postprandial glucose levels in adults with type 2 diabetes.

Likelihood Probable Evidence B
Clopidogrel (Plavix)

Theoretically, fenugreek seed might alter the clinical effects of clopidogrel by inhibiting its conversion to the active form.
Animal research shows that fenugreek seed 200 mg/kg daily for 14 days increases the maximum serum concentration of clopidogrel by 21%. It is unclear how this affects the pharmacokinetics of the active metabolite of clopidogrel; however, this study found that concomitant use of fenugreek seed and clopidogrel prolonged bleeding time by an additional 11%.

Likelihood Possible Evidence D
Metoprolol (Toprol)

Theoretically, fenugreek seed might have additive hypotensive effects when used with metoprolol.
Animal research shows that fenugreek seed 300 mg/kg daily for 2 weeks decreases systolic and diastolic blood pressure by 9% and 11%, respectively, when administered alone, and by 15% and 22%, respectively, when given with metoprolol 10 mg/kg.

Likelihood Probable Evidence B
Phenytoin (Dilantin)

Theoretically, fenugreek might decrease plasma levels of phenytoin.
Animal research shows that taking fenugreek seeds for 1 week decreases maximum concentrations and the area under the curve of a single dose of phenytoin by 44% and 72%, respectively. This seems to be related to increased clearance. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Sildenafil (Viagra)

Theoretically, concurrent use of sildenafil and fenugreek might reduce levels and therapeutic effects of sildenafil.
Animal research shows that taking fenugreek seeds for 1 week reduces maximum concentrations and the area under the curve of a single dose of sildenafil by 27% and 48%, respectively. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Theophylline

Theoretically, fenugreek may reduce the levels and clinical effects of theophylline.
Animal research shows that fenugreek 50 grams daily for 7 days reduces the maximum serum concentration (Cmax) of theophylline by 28% and the area under the plasma drug concentration-time curve (AUC) by 22%.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, fenugreek might have additive effects with warfarin and increase the international normalized ratio (INR).
Some fenugreek constituents have antiplatelet effects, although these might not be present in concentrations that are clinically significant. In one case report, a patient taking warfarin experienced an increased INR when starting to take fenugreek in combination with boldo.

Likelihood Possible Evidence D
Antihypertensive Drugs

Fenugreek may also have an additive effect on blood pressure-lowering medications. Studies on animals have shown that fenugreek seed can decrease both systolic and diastolic blood pressure by up to 22% when combined with metoprolol. Therefore, it is essential to monitor your blood pressure regularly if you are taking fenugreek and metoprolol together or any other antihypertensive drugs.

Likelihood Possible Evidence C
Fenugreek full monograph & interactions

Eurycoma5 drug types · 248 drugs

Propranolol (Inderal)

Eurycoma longifolia can reduce the levels and clinical effects of propranolol.
A small clinical study in healthy persons shows that taking a single dose of a water-based Eurycoma longifolia extract 200 mg, in combination with a single dose of propranolol 80 mg, reduces the propranolol area under the curve (AUC) by 29%, reduces the peak concentration by 42%, and increases time to peak concentration by 86% when compared with control. Since the elimination half-life of propranolol did not change, it seems that Eurycoma longifolia alters the kinetics of propranolol by decreasing its absorption in the gut, and not by altering its metabolism. It is not known if separating administration will prevent this interaction.

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

Theoretically, Eurycoma longifolia might increase levels CYP1A2 substrates.
In vitro research suggests that methanolic Eurycoma longifolia root extract weakly inhibits CYP1A2 enzymes. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2A6 (Cyp2A6) Substrates

Theoretically, Eurycoma longifolia might increase levels of CYP2A6 substrates.
In vitro research suggests that methanolic Eurycoma longifolia root extract weakly inhibits CYP2A6 enzymes. This effect has not been reported in humans.

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

Theoretically, Eurycoma longifolia might increase levels of CYP2C19 substrates.
In vitro research suggests that methanolic Eurycoma longifolia root extract weakly inhibits CYP2C19 enzymes. This effect has not been reported in humans.

Likelihood Possible Evidence D
Testosterone

Theoretically, Eurycoma longifolia may further increase levels of testosterone.
A clinical study in aging males with testosterone levels below 300 ng/dL shows that taking a specific water extract of Eurycoma longifolia roots (Physta; Biotropics Malaysia) 100-200 mg daily with breakfast for 12 weeks increases total testosterone levels by 8% to 11% when compared with placebo. It is unclear whether this increase would occur in individuals with normal testosterone levels.

Likelihood Possible Evidence D
Eurycoma full monograph & interactions

Velvet Bean extract8 drug types · 193 drugs

Levodopa

Concomitant use can increase the risk of levodopa-related adverse effects.
Cowhage contains levodopa. Some cowhage products have been standardized to contain 75-400 mg of levodopa per dose.

Likelihood Likely Evidence D
Methyldopa (Aldomet)

Theoretically, concomitant use of cowhage and methyldopa might increase the risk of hypotension.
Cowhage contains levodopa. Use of levodopa with methyldopa might cause additive hypotension. In addition, methyldopa may inhibit peripheral decarboxylation of levodopa and increase levodopa levels in the central nervous system; avoid using.

Likelihood Probable Evidence D
Monoamine Oxidase Inhibitors (Maois)

Theoretically, concomitant use of cowhage and non-selective MAOIs might increase the risk of hypertensive crisis.
Cowhage contains levodopa. Use of levodopa with non-selective MAOIs might cause hypertensive crisis. However, this interaction has not been reported with MAO-B selective inhibitors such as selegiline.

Likelihood Probable Evidence D
Anesthesia

Theoretically, concomitant use of cowhage and anesthesia might increase the risk of arrhythmias.
Cowhage contains levodopa. Use of levodopa with cyclopropane or halogenated hydrocarbon anesthesia has led to arrhythmias. Other anesthetics have not been implicated. Use other anesthetics in patients taking cowhage or tell patients to stop taking cowhage at least 2 weeks before surgery.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, concomitant use of cowhage and antidiabetes drugs might increase the risk of hypoglycemia.
Animal research shows that cowhage might have hypoglycemic effects.

Likelihood Possible Evidence D
Antipsychotic Drugs

Theoretically, use of cowhage might decrease the clinical effects of antipsychotic drugs.
Cowhage contains levodopa. Use of levodopa might counteract the antidopaminergic effects of antipsychotic medications.

Likelihood Possible Evidence D
Guanethidine (Ismelin)

Theoretically, concomitant use of cowhage and guanethidine might increase the risk of hypotension.
Cowhage contains levodopa. Use of levodopa with guanethidine might cause additive hypotension; avoid using.

Likelihood Probable Evidence D
Tricyclic Antidepressants (Tcas)

Theoretically, use of TCAs might reduce the levels and clinical effects of cowhage.
Cowhage contains levodopa. Use of TCAs might reduce the absorption of levodopa. Some case reports describe patients that developed hypertension and dyskinesia when taking both levodopa and TCAs.

Likelihood Possible Evidence D
Velvet Bean extract full monograph & interactions

Zinc10 drug types · 67 drugs

Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Theoretically, zinc might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after zinc containing products.

Likelihood Probable Evidence D
Cephalexin (Keflex)

Zinc might decrease cephalexin levels by chelating with cephalexin in the gut and preventing its absorption.
A pharmacokinetic study shows that zinc sulfate 250 mg taken concomitantly with cephalexin 500 mg decreases peak levels of cephalexin by 31% and reduces the exposure to cephalexin by 27%. Also, taking zinc sulfate 3 hours before cephalexin decreases peak levels of cephalexin by 11% and reduces the exposure to cephalexin by 18%. By decreasing cephalexin levels, zinc might increase the risk of treatment failure. This effect does not occur when zinc is taken 3 hours after the cephalexin dose. To avoid an interaction, advise patients take zinc sulfate 3 hours after taking cephalexin.

Likelihood Probable Evidence B
Cisplatin (Platinol-Aq)

Theoretically, zinc might interfere with the therapeutic effects of cisplatin.
Animal research suggests that zinc stimulates tumor cell production of the protein metallothionein, which binds and inactivates cisplatin. It is not known whether zinc supplements or high dietary zinc intake can cause clinically significant interference with cisplatin therapy. Cisplatin might also increase zinc excretion.

Likelihood Possible Evidence D
Integrase Inhibitors

Theoretically, taking zinc along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Zinc is a divalent cation. Pharmacokinetic studies have shown that other divalent cations such as calcium and iron can decrease blood levels of the integrase inhibitor dolutegravir through chelation.

Likelihood Possible Evidence D
Penicillamine (Cuprimine, Depen)

Zinc might reduce the levels and clinical effects of penicillamine.
By forming an insoluble complex with penicillamine, zinc interferes with penicillamine absorption and activity. Zinc supplements reduce the efficacy of low-dose penicillamine (0.5-1 gram/day), but do not seem to affect higher doses (1-2.75 gram/day), provided dosing times are separated. Advise patients to take zinc and penicillamine at least 2 hours apart.

Likelihood Probable Evidence B
Quinolone Antibiotics

Zinc can decrease the levels and clinical effects of quinolones antibiotics.
Quinolones form complexes with zinc in the gastrointestinal tract, reducing absorption of both the quinolone and zinc if taken at the same time. Advise patients to take these drugs at least 2 hours before, or 4-6 hours after, zinc supplements.

Likelihood Probable Evidence B
Ritonavir (Norvir)

Zinc modestly reduces levels of ritonavir.
Clinical research shows that zinc might reduce serum ritonavir levels by chelating with ritonavir in the gut and preventing its absorption. In patients with HIV, ritonavir is taken with atazanavir to prevent the metabolism and increase the effects of atazanavir. A pharmacokinetic study shows that, in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate (Solvazinc tablets) 125 mg as a single dose or as multiple daily doses for 2 weeks reduces plasma levels of ritonavir by about 16%. However, atazanavir levels still remains high enough to prevent HIV virus replication. Therefore, the decrease in ritonavir levels is not likely to be clinically significant.

Likelihood Probable Evidence B
Tetracycline Antibiotics

Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.

Likelihood Probable Evidence B
Amiloride (Midamor)

Amiloride can modestly reduce zinc excretion and increase zinc levels.
Clinical research shows that amiloride can reduce urinary zinc excretion, especially at doses of 10 mg per day or more. This zinc-sparing effect can help to counteract zinc losses caused by thiazide diuretics, but it is unlikely to cause zinc toxicity at usual amiloride doses. The other potassium-sparing diuretics, spironolactone (Aldactone) and triamterene (Dyrenium), do not seem to have a zinc-sparing effect.

Likelihood Probable Evidence B
Atazanavir (Reyataz)

Zinc modestly reduces levels of atazanavir, although this effect does not seem to be clinically significant.
Clinical research shows that zinc might decrease serum atazanavir levels by chelating with atazanavir in the gut and preventing its absorption. Although a single dose of zinc sulfate (Solvazinc tablets) 125 mg orally does not affect atazanavir concentrations in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate 125 mg daily for 2 weeks reduces plasma levels of atazanavir by about 22% in these patients. However, despite this decrease, atazanavir levels still remain at high enough concentrations for the prevention of HIV virus replication.

Likelihood Probable Evidence B
Zinc full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Alpha Testosterone, from the product label.

Shredz

See all Shredz products
Web Address
WWW.SHREDZ.COM
Pharmacist Counseling Corner

Alpha Testosterone by Shredz: Common Questions

Does Alpha Testosterone by Shredz interact with any medications?
Yes. Based on its ingredients, Alpha Testosterone has a known interaction with 739 medications, including 17 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Alpha Testosterone contains 6 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 this safe to take if I'm pregnant or breastfeeding?
No — multiple ingredients advise against it. Fenugreek is likely unsafe in pregnancy. Velvet bean extract, eurycoma, and maca should be avoided due to insufficient safety data and potential hormone effects. Velvet bean extract should not be used while breastfeeding because its levodopa content can lower prolactin and reduce milk supply. Talk to your doctor or pharmacist for personalized advice before taking any supplement during pregnancy or while nursing.
What does zinc do in this product?
Zinc supports immune function and is effective for treating zinc deficiency. In this supplement, it's included as one of the testosterone-support ingredients, though evidence for that specific use isn't in our data. Be aware that zinc can interfere with several antibiotics and antivirals if taken at the same time — spacing doses apart usually solves this.
What is velvet bean extract and why is it in here?
Velvet bean extract comes from cowhage seeds and contains levodopa — a compound that acts like a drug in your body. It's included because some research suggests it may support testosterone and sexual function, but the evidence isn't established in the data we hold. Because levodopa is so potent, this ingredient carries the biggest medication interaction risks in the product.
Can I take this with my antibiotic?
Not without spacing. Zinc in this product can reduce how much of your antibiotic your body absorbs, making the antibiotic less effective. If your antibiotic is a quinolone, tetracycline, or cephalexin, take the antibiotic at least 2–6 hours before or after this supplement. Ask your pharmacist which timing is best for your specific antibiotic.
What are the most common side effects of taking this?
From zinc: nausea, vomiting, abdominal cramps, diarrhea, and a metallic taste, especially at higher doses. From fenugreek: bloating, diarrhea, and abdominal pain. From velvet bean extract: diarrhea, flatulence, and insomnia in a small number of users. Most adverse effects are mild and dose-related.
Does this product contain any fillers or inactive ingredients?
Yes — it includes gelatin, rice flour, magnesium stearate, titanium dioxide, and food colorings (FD&C Red #40 and FD&C Blue #1) as inactive ingredients to make and preserve the capsule.

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.

Alpha Testosterone label
Go deeper

The Full Monographs Behind Alpha Testosterone’s Ingredients

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

Herb & supplement monograph

Zinc

Interacts with 67 drugs

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but supplements can help correct or prevent a defici...

Read the full Zinc monograph → Herb & supplement monograph

Maca

Maca is a nutrient-rich Andean root often used for energy, libido, and menopause symptoms. Early studies suggest it may modestly help sexual desire and some menopause symptoms, but the evide...

Read the full Maca monograph → Herb & supplement monograph

Pellitory

Pellitory (often Anacyclus pyrethrum, the root traditionally called 'pellitory of Spain') is an herb chiefly known in folk and traditional medicine for numbing toothache and stimulating sali...

Read the full Pellitory monograph → Herb & supplement monograph

Eurycoma Longifolia

Interacts with 248 drugs

Eurycoma longifolia (tongkat ali) is a Southeast Asian herb most popular for supporting testosterone, libido, and male fertility, with some small human studies suggesting possible benefits....

Read the full Eurycoma Longifolia monograph → Herb & supplement monograph

Fenugreek

Interacts with 389 drugs

Fenugreek is a common kitchen spice that is also taken as a supplement, mainly for blood sugar, cholesterol, and to support breast milk production. Some early research is encouraging for blo...

Read the full Fenugreek monograph → Herb & supplement monograph

Cowhage

Interacts with 193 drugs

Cowhage (Mucuna pruriens) is a tropical legume best known as a natural source of L-dopa, the compound the body turns into dopamine. It is most studied for Parkinson's disease symptoms and ma...

Read the full Cowhage monograph →
Sources

Sources & How We Checked

Alpha Testosterone'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 136 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.

Zinc 88 references
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  4. Blondeau JM. Expanded activity and utility of the new fluoroquinolones: a review. Clin Ther 1999;21:3-40. PubMed
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  21. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  22. Age-Related Eye Disease Study Research Group. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss. AREDS report no. 8. Arch Oph
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  33. Polk RE, Healy DP, Sahai J, et al. Effect of ferrous sulfate and multivitamins with zinc on absorption of ciprofloxacin in normal volunteers. Antimicrob Agents Chemother 1989;33:1841-4. PubMed
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  35. Penttila O, Hurme H, Neuvonen PJ. Effect of zinc sulfate on the absorption of tetracycline and doxycycline in man. Eur J Clin Pharmacol 1975;9:131-4.
  36. Kondo Y, Yamagata K, Satoh M, et al. Optimal administration schedule of cisplatin for bladder tumor with minimal induction of metallothionein. J Urol 2003;170:2467-70. PubMed
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  46. Tisdall FF, Brown A, Defries RD. Persistent anosmia following zinc sulfate nasal spraying. JPed 1938;18:60-2. DOI
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  51. Health Canada / GlaxoSmithKline Consumer Healthcare. Association of long-term, excessive use of zinc-containing Poli-Grip products with myeloneuropathy and blood dyscrasias. February 18, 2010. Available at: http://hc-sc.gc.ca/dhp-mps/alt_formats/pdf/medef
  52. GlaxoSmithKline Consumer Advisory. GlaxoSmithKline (GSK) warns about a potential health risk associated with long-term, excessive use of GSK's zinc-containing denture adhesives Super Polygrip Original, Ultra Fresh and Extra Care. February 18, 2010. Availa
  53. Science M, Johnstone J, Roth DE, et al. Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials. CMAJ 2012;184:E551-61. PubMed
  54. Castilla-Higuero, L., Romero-Gomez, M., Suarez, E., and Castro, M. Acute hepatitis after starting zinc therapy in a patient with presymptomatic Wilson's disease. Hepatology 2000;32(4 Pt 1):877. PubMed
  55. Sharquie, K. E., Najim, R. A., Farjou, I. B., and Al Timimi, D. J. Oral zinc sulphate in the treatment of acute cutaneous leishmaniasis. Clin.Exp.Dermatol. 2001;26(1):21-26. PubMed
  56. Dreno, B., Moyse, D., Alirezai, M., Amblard, P., Auffret, N., Beylot, C., Bodokh, I., Chivot, M., Daniel, F., Humbert, P., Meynadier, J., and Poli, F. Multicenter randomized comparative double-blind controlled clinical trial of the safety and efficacy of
  57. Moore, R. Bleeding gastric erosion after oral zinc sulphate. Br.Med J 3-25-1978;1(6115):754. PubMed
  58. Jafek, B. W., Linschoten, M. R., and Murrow, B. W. Anosmia after intranasal zinc gluconate use. Am J Rhinol. 2004;18(3):137-141. DOI
  59. Simonart, T. and de, Maertelaer, V. Systemic treatments for cutaneous warts: a systematic review. J Dermatolog.Treat. 2012;23(1):72-77. PubMed
  60. Cochran, R. J., Tucker, S. B., and Flannigan, S. A. Topical zinc therapy for acne vulgaris. Int.J Dermatol. 1985;24(3):188-190. DOI
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  63. Lang, C. J., Rabas-Kolominsky, P., Engelhardt, A., Kobras, G., and Konig, H. J. Fatal deterioration of Wilson's disease after institution of oral zinc therapy. Arch Neurol. 1993;50(10):1007-1008. PubMed
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  65. Varas Lorenzo, M. J. Zinc acexamate and ranitidine in the short- and mid-term management of gastroduodenal ulcers. Curr Ther Res 21986;39:19-29.
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  67. DeCook, C. A. and Hirsch, A. R. Anosmia due to inhalational zinc: a case report (abstract). Chem Senses 2000;25:659.
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  69. Dadamio J, Van Tournout M, Teughels W, Dekeyser C, Coucke W, Quirynen M. Efficacy of different mouthrinse formulations in reducing oral malodour: a randomized clinical trial. J Clin Periodontol. 2013 May;40(5):505-13. PubMed
  70. Moyle G, Else L, Jackson A, Back D, Yapa MH, Seymour N, Ringner-Nackter L, Karolia Z, Gazzard B, Boffito M. Coadministration of atazanavir-ritonavir and zinc sulfate: impact on hyperbilirubinemia and pharmacokinetics. Antimicrob Agents Chemother. 2013 Aug PubMed
  71. Zittel S, Ufer F, Gerloff C, Münchau A, Rosenkranz M. Severe myelopathy after denture cream use--is copper deficiency or excess zinc the cause? Clin Neurol Neurosurg. 2014 Jun;121:17-8. PubMed
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  74. Ding Y, Jia YY, Li F, et al. The effect of staggered administration of zinc sulfate on the pharmacokinetics of oral cephalexin. Br J Clin Pharmacol. 2012 Mar;73(3):422-7. PubMed
  75. Fallah R, Sabbaghzadegan S, Karbasi SA, Binesh F. Efficacy of zinc sulfate supplement on febrile seizure recurrence prevention in children with normal serum zinc level: A randomised clinical trial. Nutrition. 2015;31(11-12):1358-61. PubMed
  76. Lazzerini M, Wanzira H. Oral zinc for treating diarrhoea in children. Cochrane Database Syst Rev. 2016;12:CD005436. PubMed
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  78. Nagraj SK, George RP, Shetty N, Levenson D, Ferraiolo DM, Shrestha A. Interventions for managing taste disturbances. Cochrane Database Syst Rev. 2017 Dec 20;12(12):CD010470. PubMed
  79. Yee BE, Richards P, Sui JY, Marsch AF. Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis. Dermatol Ther. 2020:e14252. PubMed
  80. Janyajirawong R, Vilaichone RK, Sethasine S. Efficacy of zinc supplement in minimal hepatic encephalopathy: A prospective, randomized controlled study (Zinc-MHE Trial). Asian Pac J Cancer Prev 2021;22(9):2879-2887. PubMed
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  86. Sivakumar RR, Chinnaiah Govindareddy D, Sahoo J, Bobby Z, Chinnakali P. Effect of daily zinc supplementation for 12 weeks on serum thyroid auto-antibody levels in children and adolescents with autoimmune thyroiditis - a randomized controlled trial. J Pedi PubMed
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See these in context on the Zinc monograph →

Maca 1 reference
  1. Valerio, L. G., Jr. and Gonzales, G. F. Toxicological aspects of the South American herbs cat's claw (Uncaria tomentosa) and Maca (Lepidium meyenii) : a critical synopsis. Toxicol.Rev 2005;24(1):11-35. PubMed

See these in context on the Maca monograph →

Pellitory 1 reference
  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

See these in context on the Pellitory monograph →

Eurycoma Longifolia 4 references
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  2. Tambi MI, Imran MK, Henkel RR. Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism? Andrologia 2011 Jun 15. doi: 10.1111/j.1439-0272.2011.01168.x. [Epub ahead of pri PubMed
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See these in context on the Eurycoma Longifolia monograph →

Fenugreek 30 references
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  20. Reeder C, Legrand A, O'Connor-Von SK. The Effect of Fenugreek on Milk Production and Prolactin Levels in Mothers of Preterm Infants. Clinical Lactation 2013;4(4):159-165. DOI
  21. Al-Jenoobi FI, Ahad A, Mahrous GM, Al-Mohizea AM, AlKharfy KM, Al-Suwayeh SA. Effects of fenugreek, garden cress, and black seed on theophylline pharmacokinetics in beagle dogs. Pharm Biol 2015;53(2):296-300. PubMed
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  23. Steels E, Rao A, Vitetta L. Physiological aspects of male libido enhanced by standardized Trigonella foenum-graecum extract and mineral formulation. Phytother Res. 2011 Sep;25(9):1294-300.
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  29. Al-Mohizea AM, Ahad A, El-Maghraby GM, et al. Effects of Nigella sativa, Lepidium sativum and Trigonella foenum-graecum on sildenafil disposition in beagle dogs. Eur J Drug Metab Pharmacokinet. 2015;40(2):219-24. PubMed
  30. Alkharfy KM, Al-Jenoobi FI, Al-Mohizea AM, et al. Effects of Lepidium sativum, Nigella sativa and Trigonella foenum-graceum on phenytoin pharmacokinetics in beagle dogs. Phytother Res. 2013;27(12):1800-4.

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Cowhage 12 references
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  8. Akhtar MS, Qureshi AQ, Iqbal J. Antidiabetic evaluation of Mucuna pruriens, Linn seeds. J Pak Med Assoc 1990;40:147-50.
  9. Prakash, D., Niranjan, A., and Tewari, S. K. Some nutritional properties of the seeds of three Mucuna species. Int.J.Food Sci.Nutr. 2001;52(1):79-82.
  10. Vadivel, V. and Janardhanan, K. Nutritional and antinutritional characteristics of seven South Indian wild legumes. Plant Foods Hum.Nutr 2005;60(2):69-75. PubMed
  11. Creapure (Creatine Monohydrate). Toxicological Datasheet. Degussa BioActives. Available at: https://www.fda.gov/ohrms/DOCKETS/.../95s-0316-rpt0154-54-Ref-50-vol112.pdf.
  12. Pulikkalpura H, Kurup R, Mathew PJ, Baby S. Levodopa in Mucuna pruriens and its degradation. Sci Rep 2015;5:11078. PubMed

See these in context on the Cowhage monograph →

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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.

© 2021 Therapeutic Research Center, LLC

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