Why is piperine added to supplements, and is it safe?

Piperine, the pungent compound in black pepper, is added to supplements because it can raise how much of another ingredient, most often curcumin, reaches the blood. It is generally treated as low risk in the small amounts found in supplements, but the same effect that helps absorption can also change how some prescription drugs behave, so it is worth understanding before you buy.

This guide covers what piperine does, what the human studies actually used, what a "BioPerine 5 mg" line on a label means, and which questions to ask if you take medication. It is general information, not medical advice.

Why is piperine added to supplements?

Many plant compounds are poorly absorbed. Curcumin, the main active compound in turmeric, is the textbook case: the gut wall and liver break it down quickly, so very little reaches the blood. The NCCIH page on turmeric says oral curcumin products often contain substances from other plants, such as piperine from black pepper, and that combining curcumin with piperine is one way to improve its bioavailability.

That is the whole reason for the ingredient. Piperine is not added for its own benefits. It is added as a helper, and the label line usually reads "black pepper extract," "BioPerine" (a branded extract) or "standardized to 95% piperine."

The 1998 study that started this trend describes piperine as a known inhibitor of glucuronidation, one of the ways the liver and intestinal wall clear curcumin quickly. In plain terms, piperine slows down the body's clean-up of the other ingredient, so more of it stays in the blood for longer.

What do the human studies show?

The study behind most "with piperine" marketing is a 1998 paper in Planta Medica by Shoba and colleagues. In healthy volunteers, 2 g of curcumin alone gave serum levels that were either undetectable or very low. When 20 mg of piperine was taken with it, the authors reported a 2000% increase in bioavailability, with no adverse effects at those doses. In rats the same approach raised bioavailability by 154%.

Two details matter. First, the human dose of curcumin was large (2 g) and the piperine dose was 20 mg. Second, the study measured blood levels of curcumin, not any health outcome. A higher blood level is not the same as a benefit.

A second study looked at a smaller piperine dose. Badmaev and colleagues gave 90 mg or 120 mg of coenzyme Q10 with either placebo or 5 mg of piperine to healthy adult men in a double-blind design. The single-dose and 14-day experiments showed smaller increases that were not statistically significant. After 21 days on 120 mg of coenzyme Q10, the piperine group had an area under the plasma curve about 30% larger than the placebo group (p = 0.0348).

So the evidence is real but narrow. It shows that piperine can raise blood levels of certain compounds in small studies of healthy volunteers. It does not show that any given supplement works for any condition, and a result with one ingredient and one dose does not automatically carry over to a different formula.

What does "BioPerine 5 mg" on a label mean?

A label line such as "black pepper fruit extract (BioPerine, standardized to 95% piperine) 5 mg" tells you the weight of the extract, not the weight of piperine. At 95%, a 5 mg extract holds roughly 4.75 mg of piperine. That is close to the 5 mg used in the coenzyme Q10 study, and below the 20 mg used in the curcumin study.

The Joint Genesis review lists exactly this: BioPerine at 5 mg, which our review rates as a standard amount for an absorption helper. The Joint N-11 review shows the same 5 mg line, on a label where every ingredient has a stated amount. Having the number is what lets you compare it with a study at all.

Many products give you nothing to compare. The Ikaria Lean Belly Juice review notes that black pepper extract "standardized to 95% piperine" sits inside a 1,000 mg blend of nine ingredients, so the amount of piperine is not separately stated. The iGenics review notes that the sales page mentions turmeric with bioperine but never states how much of any ingredient the capsule contains. In the Quietum Plus review, "Ashwagandha & Piperine" is listed as a pair with no amount.

A piperine line with no milligrams is a signal, not proof of anything wrong. It means you cannot tell whether the helper is present at a meaningful amount, and you cannot tell whether the main ingredient is dosed anywhere near a study.

Does piperine interact with medications?

It can, and this is the part most sales pages skip. A 2002 study in the Journal of Pharmacology and Experimental Therapeutics found that piperine inhibits the drug transporter P-glycoprotein and the major drug-metabolizing enzyme CYP3A4 in laboratory systems (cell layers and human liver microsomes). The authors concluded that dietary piperine could affect the blood levels of drugs handled by those two proteins, particularly drugs taken by mouth.

Human data point the same way for several drugs. A 2005 literature review of herb-drug interactions summarizes it this way: piperine from black and long pepper increased the exposure to phenytoin, propranolol and theophylline in healthy volunteers, and raised rifampin levels in patients with pulmonary tuberculosis. Phenytoin is an anti-seizure drug, propranolol a heart and blood pressure drug, theophylline an asthma drug and rifampin an antibiotic.

There is a counterweight. In a placebo-controlled crossover study of eight healthy volunteers, a curcuminoid and piperine extract (4 g of curcuminoids plus 24 mg of piperine, taken four times over 2 days) produced no meaningful change in the blood levels of midazolam, flurbiprofen or paracetamol. Interactions depend on the drug, the dose and the product, which is why a blanket "it is safe" and a blanket "it is dangerous" are both wrong.

The practical point is simple. If you take a prescription drug with a narrow safety margin, such as an anti-seizure drug or a heart medicine, ask your doctor or pharmacist before adding any supplement that lists black pepper extract or piperine.

Is piperine safe, and what about the liver?

The 1998 curcumin study reported no adverse effects at the doses it used, and the 2013 interaction study above enrolled healthy volunteers for a short course. Those are short, small studies, so they cannot settle long-term safety for people who take a product every day for months.

The NCCIH turmeric page raises a separate point worth knowing: liver damage has been reported in some people who consumed highly bioavailable curcumin formulations. It tells readers to stop the product and talk with a health care provider if they notice fatigue, nausea, poor appetite, dark urine or jaundice. That page covers curcumin products in general and does not single out piperine. But because piperine's job is to increase exposure, a curcumin plus piperine product deserves the same caution as any other bioavailability-boosted formula.

Also remember how this market works. The same NCCIH page notes that dietary supplements are not approved by the FDA before they are sold, so a label line about better absorption is the maker's statement, not a regulator's finding.

A short checklist before you buy a product with piperine

1. Find the piperine or black pepper line and write down the milligrams. If there is no number, treat the claim as unverified.
2. Check whether the amount is of extract or of piperine. "5 mg extract, 95% piperine" is about 4.75 mg of piperine.
3. Look at the main ingredient it is meant to help. Is that amount stated too? A helper with no partner dose tells you little.
4. Ask whether the studies cited on the page measured blood levels or a real outcome. Higher levels alone do not prove a benefit.
5. Read the refund terms before you pay. Our how we review supplements page explains how we compare label doses with research.
6. Tell your doctor or pharmacist if you take any prescription medication, and stop and call a provider if you notice liver warning signs.

For more examples of how labels handle doses, browse our supplement reviews and compare how each one treats its label.

FAQ

Does black pepper extract help curcumin absorb better?

In a 1998 study of healthy volunteers, 20 mg of piperine taken with 2 g of curcumin raised curcumin's bioavailability by 2000% compared with curcumin alone. That shows higher blood levels in a small study, not a proven health benefit.

How much piperine is in a typical supplement?

Some labels list 5 mg of a 95% extract, which is about 4.75 mg of piperine. Others give no amount at all. The studies we opened used 5 mg in one case and 20 mg in several others, so there is no single standard.

Can piperine interact with my medicine?

It can for some drugs. A literature review reports higher blood levels of phenytoin, propranolol and theophylline when taken with piperine, while one study of a curcumin and piperine extract found no change for three other drugs. Ask your doctor or pharmacist before combining it with any prescription drug.

Is piperine the same as BioPerine?

BioPerine is a brand name for a black pepper fruit extract standardized to contain piperine, often 95%. When a label says BioPerine, the amount listed is the extract, not pure piperine.