Safety · 3 min read
Black Pepper Extract And Your Other Medicines
Five of HoneyPower’s six ingredients are there to do something to you. The sixth is there to do something to the other five — and to whatever else you take.
Black pepper extract is in formulas for its active constituent, piperine, which inhibits CYP3A4, CYP2C9 and P-glycoprotein — three of the main routes substances leave the body by.
That is not a side effect. It is the reason it is in there: slowing clearance raises the blood level of whatever else is present.
The studied amounts are small. 20 mg a day for ten days raised carbamazepine exposure by 48%, and diclofenac and fexofenadine by 68% each.
HoneyPower declares no amount of black pepper extract and no piperine figure. So there is no way to tell from the supplied material whether a serving is nowhere near 20 mg or well past it.
What the studies measured
The interaction evidence is unusually concrete for a botanical, because the studies gave volunteers a known dose of piperine alongside a known dose of a prescription drug and measured what happened.
| Drug | What it is | Exposure (AUC) | Piperine dose |
|---|---|---|---|
| Carbamazepine | an anti-seizure medicine | +48% | 20 mg/day, 10 days |
| Diclofenac | an anti-inflammatory | +68% | 20 mg/day, 10 days |
| Fexofenadine | an antihistamine | +68% | 20 mg/day, 10 days |
| Midazolam | a sedative | half-life prolonged, sedation deepened | 15 mg/day, 3 days |
Preliminary evidence in the same summary suggests piperine also raises concentrations of chlorzoxazone, propranolol and theophylline, with warfarin and digoxin named as plausible but unconfirmed.
Why the missing number matters more here than anywhere else on the label
An undeclared amount of maca is an unanswerable question about whether the maca does anything. An undeclared amount of piperine is an unanswerable question about everything else you take.
The ingredient with the clearest dose-response evidence on the label is the one with no dose on it.
And the studied figures are not large. Fifteen to twenty milligrams is a plausible amount for a bioavailability enhancer in a six-ingredient capsule — which is precisely why the figure should be readable, and precisely why its absence is the one gap on this label with a practical consequence.
What to do about it, concretely
- 1
If you take nothing on prescription
This is a smaller issue. Black pepper is a food and the quantities in a capsule are unlikely to be dramatic. Read the panel when it arrives anyway.
- 2
If you take anything on prescription
Take the bottle to a pharmacist before the first capsule. Not a list typed into a search box — the bottle, so they can read the panel.
- 3
Ask one specific question
Is anything I take cleared by CYP3A4, CYP2C9 or P-glycoprotein?
A pharmacist can answer that in under a minute from your record. - 4
Check the panel for a standardisation figure
A well-specified extract will give a piperine percentage. That is the number that turns this from an open question into an arithmetic one.
Questions
Is black pepper extract dangerous?
On its own, in food amounts, it is black pepper. The documented concern is not toxicity but interaction — it raises the blood level of other things. Whether that matters to you depends entirely on what else you take.
Why do supplements put it in at all?
To raise the absorption of the other ingredients. It is a legitimate formulation choice and it is used in many reputable products. The issue on this label is the undeclared amount, not the ingredient.
How much piperine is in a normal meal?
The summary this post draws on notes it is unclear whether dietary black pepper causes clinically significant interactions, but that heavy users may reach a similar amount to the studies. A capsule of standardised extract is a different proposition from seasoning.
Sources
- Piperine Drug InteractionsPharmacy TimesThe interaction evidence for black pepper extract. At 20 mg a day for 10 days piperine raised carbamazepine exposure (AUC) by 48%, diclofenac by 68% and fexofenadine by 68%; at 15 mg a day for 3 days it prolonged midazolam’s half-life and deepened its sedation. The mechanisms named are inhibition of CYP3A4, CYP2C9 and P-glycoprotein.
- Dietary Supplement Labeling Guide, Chapter IV: Nutrition LabelingU.S. Food and Drug AdministrationThe document this whole site is about, and the reason the absence of a panel matters. Question 30: “You must list the quantitative amount by weight per serving immediately following the name of the dietary ingredient.” Question 3: “You must list the names and quantities of dietary ingredients present in your product.” Question 34 covers proprietary blends, which must carry the total weight of the blend and list its ingredients in descending order by weight. The guidance is marked “Contains Nonbinding Recommendations.”
What this page was checked against
Every figure on it is transcribed from the supplied Supplement Facts panel and checked-out pack, derived by arithmetic from those, or taken from a source on the references page.