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Dietary supplement

Tribulus 500 mg Ingredients & Drug Interactions

by NOW Sports

Capsule Category: Botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Tribulus 500 mg is a dietary supplement by NOW Sports with 1 active ingredient. Its ingredients are commonly taken for low libido and sexual function, athletic performance and muscle building, testosterone support.Based on those ingredients, 259 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Tribulus terrestris Aerial Parts, Fruit Extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Tribulus 500 mg by NOW Sports

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

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 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: Tribulus terrestris Aerial Parts, Fruit Extract at 500 mg per capsule. Tribulus is a plant extract traditionally used for sexual function and athletic performance.

The capsule also contains inactive ingredients — hypromellose, rice flour, silicon dioxide, and magnesium stearate — which are fillers, binders, and capsule material.

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: enhance vitality and support men's health.
  • We looked for evidence on: Athletic performance, Erectile dysfunction (ED), Exercise-induced muscle damage, Male infertility, Sexual dysfunction, testosterone support — and 1 related terms.
  • The strongest evidence on file: Tribulus is rated "Possibly Effective" for Sexual dysfunction (Natural Medicines).
  • Also on file: Tribulus is rated "Possibly Ineffective" for Athletic performance.
  • Also on file: Tribulus is rated "Insufficient Reliable Evidence To Rate" for Erectile dysfunction (ED), Male infertility, Exercise-induced muscle damage.

Tribulus shows possibly effective evidence for sexual dysfunction, suggesting it may help in this area, though the evidence isn't definitive. For athletic performance, the evidence points to possibly ineffective — meaning it's unlikely to deliver what people hope for in that regard.

For benign prostatic hyperplasia (enlarged prostate), we don't have reliable evidence to rate it one way or the other.

The evidence, ingredient by ingredient Tribulus

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 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Tribulus is generally well tolerated short-term in healthy adults, but long-term safety data and product quality information are limited. The most common side effects are gastrointestinal — abdominal pain, cramping, nausea, vomiting, diarrhea, or constipation — though in one study these rates were similar to placebo.

Rare serious effects including liver and kidney injury, seizures, and prolonged painful erection have been reported. Do not use tribulus during pregnancy — the safety data advises against it because it may affect hormones.

Avoid it while breastfeeding as well, since we don't have reliable safety information for nursing infants.

Side effects, ingredient by ingredient Tribulus

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?
  • 1 of the 1 matched ingredient can interact with medications — Tribulus.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: diabetes medications; lithium.
  • For scale: 259 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 you take this product, double-check your medications with your pharmacist or our search tool. The main concerns are blood pressure medications (risk of pressure dropping too low), diabetes drugs (risk of low blood sugar), and lithium (risk of elevated levels).

These are Moderate-severity interactions and deserve a quick conversation.

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.

Tribulus may be worth considering if you're interested in sexual function support and have no blood pressure or diabetes medications, and you're not pregnant or nursing. If you take antihypertensives, diabetes drugs, or lithium, you need to check with your pharmacist first — the interaction risks are real.

Talk to us before starting, especially if you're on any regular medications.

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

Assessment coverage: 1 of 1 active ingredient 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 Tribulus 500 mg, straight from the product label.

Brand NOW Sports
Barcode (UPC) 733739021700
Net contents 100 Veg Capsule(s)
Market status On market
Date entered into DSLD Aug 22, 2024
DSLD ID 314506
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Kosher, Adult Male (18-50 Years), Gluten Free, Dairy 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 Tribulus 500 mg by NOW Sports, 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:
1 Veg Capsule(s)
Maximum serving Sizes:
1 Veg Capsule(s)
Servings per container
100
UPC/BARCODE
733739021700
IngredientAmount% DV
Tribulus terrestris Aerial Parts, Fruit Extract500 mg--

Other ingredients: Hypromellose, Rice Flour, Silicon Dioxide, Magnesium Stearate

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.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 1 capsule 1 to 3 times daily with food.

Formula

Tribulus terrestris has been used for centuries in ancient Greece, India and Africa to enhance vitality and virility. Recent research indicates that Tribulus can support the body’s free radical defense systems and preliminary studies suggest that Tribulus may help to promote healthy endocrine function and male reproductive health.

Men's health

Tribulus 500 MG Standardized Extract

Triangle K (Kosher)

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.

Precautions

Caution: For adults only.

Consult physician if pregnant/nursing, taking medication, or have a medical condition.

Keep out of reach of children.

Not manufactured with yeast, wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

Seals/Symbols

GMP Quality Assured

Triangle K (Kosher)

Formulation

Vitality

Non-GMO

V Vegan

Made and quality tested in the USA with globally sourced ingredients.

Not manufactured with yeast, wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients.

Natural color variation may occur in this product.

FDA Statement of Identity

A Dietary Supplement

Storage

Store in a cool, dry, dark place after opening.

See for yourself

Tribulus 500 mg by NOW Sports label

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

What’s inside

The Ingredients in Tribulus 500 mg by NOW Sports

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Veg Capsule(s) Dosage formCapsule Servings per container100 Amounts shown are per serving.

500 mg per serving Form: Tribulus terrestris Aerial Parts Extract, Tribulus terrestris Fruit Extract

Tribulus is a plant supplement most often marketed to boost libido, testosterone, and athletic performance, but the human evidence behind these claims...

Tribulus terrestris Aerial Parts, Fruit Extract monograph & interactions

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

Interaction report

Tribulus 500 mg by NOW Sports Drug Interactions

Want to check YOUR meds against Tribulus 500 mg?

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
259Drugs
259 Moderate

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in Tribulus 500 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Tribulus terrestris Aerial Parts, Fruit Extract3 drug types · 259 drugs

Antidiabetes Drugs

Taking tribulus with antidiabetes drugs might increase the risk of hypoglycemia.
Clinical research shows that Tribulus can lower blood glucose levels in adults with type 2 diabetes who are taking antidiabetes medications.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, taking tribulus with antihypertensive drugs might increase the risk of hypotension.
Animal research shows that tribulus can lower blood pressure by inhibiting angiotensin-converting enzyme (ACE). Tribulus has also demonstrated hypotensive effects in pre-hypertensive adults.

Likelihood Possible Evidence D
Lithium

Theoretically, tribulus might increase the levels and clinical effects of lithium.
Tribulus is thought to have diuretic properties. Due to these potential diuretic effects, tribulus might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
The maker

Brand information

Manufacturer and brand details for Tribulus 500 mg, from the product label.

NOW Sports

See all NOW Sports products
Name
NOW FOODS
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowsportsproducts.com
Pharmacist Counseling Corner

Tribulus 500 mg by NOW Sports: Common Questions

Does Tribulus 500 mg by NOW Sports interact with any medications?
Yes. Based on its ingredients, Tribulus 500 mg has a known interaction with 259 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Tribulus 500 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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.
Can I take Tribulus if I'm pregnant or breastfeeding?
No — tribulus is possibly unsafe in pregnancy because it may affect hormones and safety isn't established. Avoid it while breastfeeding too, since we don't have reliable safety data for that situation. Talk to your doctor about your options.
What are the side effects?
Most commonly, people report stomach upset — cramping, nausea, vomiting, diarrhea, or constipation — though one study found these rates matched placebo. Serious side effects are rare but have included liver and kidney injury, seizures, and prolonged painful erection. If you notice anything unusual, stop and contact us.
Does tribulus actually improve athletic performance?
The evidence suggests it's likely ineffective for that purpose, so if athletic gains are your main goal, this probably isn't the right choice.
How much data do we have on long-term use?
Not much — tribulus is well tolerated in the short term, but we're missing good quality and long-term safety information, so we can't tell you what happens with years of use.
Does this product have any fillers or inactive ingredients?
Yes, the capsule contains hypromellose, rice flour, silicon dioxide, and magnesium stearate as inactive ingredients — these are standard binders and fillers.
What is tribulus used for?
Tribulus is traditionally used for sexual function — the evidence shows it may help — and it's also marketed for athletic performance, though data suggests that's unlikely to work. Some people try it for prostate health, but we don't have enough reliable evidence to say whether it helps there.

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

Not sure if Tribulus 500 mg is safe with your meds?

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Ask a pharmacist

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.

Tribulus 500 mg label
Sources

Sources & How We Checked

Tribulus 500 mg'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 10 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.

Tribulus 10 references
  1. Sharifi AM, Darabi R, Akbarloo N. Study of antihypertensive mechanism of Tribulus terrestris in 2K1C hypertensive rats: role of tissue ACE activity. Life Sci 2003;73:2963-71. PubMed
  2. Walker D, Bird A, Flora T, O'Sullivan B. Some effects of feeding Tribulus terrestris, Ipomoea lonchophylla and the seed of Abelmoschus ficulneus on fetal development and the outcome of pregnancy in sheep. Reprod Fertil Dev 1992;4:135-44. PubMed
  3. Al-Ali M, Wahbi S, Twaij H, Al-Badr A. Tribulus terrestris: preliminary study of its diuretic and contractile effects and comparison with Zea mays. J Ethnopharmacol 2003;85:257-60. PubMed
  4. Tabakova, P., Dimitrov, M., Ognyanov, K., and et al. Clinical study of Tribestan in females with endocrine sterility. Documentation for Registration (unpublished) 1999.
  5. Akhtari E, Raisi F, Keshavarz M, et al. Tribulus terrestris for treatment of sexual dysfunction in women: randomized double-blind placebo-controlled study. Daru 2014;22:40. PubMed
  6. Ryan M, Lazar I, Nadasdy GM, et al. Acute kidney injury and hyperbilirubinemia in a young male after ingestion of Tribulus terrestris. Clin Nephrol 2015;83(3):177-83. PubMed
  7. Postigo S, Lima SM, Yamada SS, et al. Assessment of the effects of Tribulus terrestris on sexual function of menopausal women. Rev Bras Ginecol Obstet 2016;38(3):140-6. PubMed
  8. Talasaz AH, Abbasi MR, Abkhiz S, Dashti-Khavidaki S. Tribulus terrestris-induced severe nephrotoxicity in a young healthy male. Nephrol Dial Tranplant 2010;25(11):3792-3. PubMed
  9. Samani NB, Jokar A, Soveid M, Heydari M, Mosavat SH. Efficacy of the hydroalcoholic extract of Tribulus terrestris on the serum glucose and lipid profile of women with diabetes mellitus: a double-blind randomized placebo-controlled clinical trial. J Evid
  10. Siddiqui MA, Itrat M, Mobeen A, Khan MI. Efficacy of khar-i-khasak (Tribulus terrestris Linn.) in prehypertension: a randomized, double-blind, placebo-controlled trial. J Complement Integr Med. 2021.

See these in context on the Tribulus 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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