NutriStack
Berberine HCl and Losartan, a caution.
Berberine HCl can inhibit CYP2C9 activity and may alter losartan conversion to its active metabolite E-3174. Berberine HCl may also lower blood pressure, so the combination could change blood pressure response or increase lightheadedness in sensitive users.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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At a glance
- Substances
- Berberine HCl and Losartan
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Moderate evidence
Caution
What is happening. Berberine HCl can inhibit CYP2C9 activity and may alter losartan conversion to its active metabolite E-3174. Berberine HCl may also lower blood pressure, so the combination could change blood pressure response or increase lightheadedness in sensitive users.
Mechanism. Losartan is converted partly by CYP2C9 to E-3174, an active metabolite. Repeated berberine dosing inhibited CYP2C9 in humans, doubled the losartan to E-3174 ratio, and berberine has modest blood-pressure-lowering effects in clinical trials.
Recommendation. If you use berberine HCl with losartan, start berberine HCl cautiously and monitor home blood pressure during the first 1 to 2 weeks. Report dizziness, fainting, unusual fatigue, or loss of blood pressure control to your prescriber.
Sources (3)
- Guo Y, Chen Y, Tan ZR, Klaassen CD, Zhou HH. Repeated administration of berberine inhibits cytochromes P450 in humans. European Journal of Clinical Pharmacology. 2012;68(2):213-217. PMID 21870106
- Park YA, Song YB, Yee J, et al. Influence of CYP2C9 Genetic Polymorphisms on the Pharmacokinetics of Losartan and Its Active Metabolite E-3174: A Systematic Review and Meta-Analysis. Journal of Personalized Medicine. 2021;11(7):617. PMID 34210056
- Lan J, Zhao Y, Dong F, et al. Meta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension. Journal of Ethnopharmacology. 2015;161:69-81. PMID 25498346
Stack Score
How this pair moves the number.
Effect on the composite score
If both Berberine HCl and Losartan are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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