Juniper berry
Juniper berry comes from Juniperus communis, the plant behind gin. In pre-workouts it is there for a diuretic effect, meant to give a tighter and more vascular look. That is the promise. Human research testing that promise does not exist.
What the research shows
No sound research in humans.
There is not a single human study on juniper berry and fluid loss, blood flow or athletic performance. Its reputation as a diuretic comes from animal research, where terpinen-4-ol increases flow through the kidney. Two randomised human trials from 2025 cover entirely different ground, namely indigestion and menstrual pain, and they say nothing about the promise on the tub.
Who it makes sense for: For nobody who buys a pre-workout to train better. Anyone who wants to feel drier in the gym may expect something from it, though that is expectation and not evidence. During pregnancy or with kidney problems, leave it alone.
How we weigh evidenceOrigin
NaturalThe berry of the juniper shrub, which grows across Europe. In cooking it turns up in game dishes and sauerkraut, and it gives gin its flavour. What you get from food stays far below the amount in a supplement.
Safety
Short-term use of the berry is considered safe. The German Commission E advises against more than four weeks in a row, because high doses of the oil can irritate the kidneys. Juniper is advised against during pregnancy since it can cause uterine contractions, and caution applies with kidney problems. A diuretic alongside training in the heat works against your fluid balance.
For comparison
A pre-workout serving with 150 mg of extract delivers far more than a plate of sauerkraut, and there is no reason to assume those 150 mg do anything. With creatine or caffeine we know exactly at which amount the effect starts. Here we do not.
Dosage by weight and gender
There is no clinical dosage, because no study has established one. The 100 to 200 mg found on labels is practice and not evidence. Body weight plays no role here either: without a demonstrated effect there is nothing to scale.
Scientific sources
The clinical dosages on this page are based on peer-reviewed research.
- Potential of Juniperus communis L as a nutraceutical in human and veterinary medicineRaina R et al. (2019)
- Botanical medicines for the urinary tractYarnell E (2002)
- Efficacy and safety of Roleca® juniper 100 mg in the treatment of functional dyspepsia: A randomized, double-blind, placebo-controlled trialAlbrecht U et al. (2025)
- Efficacy and safety of abhal (Juniperus communis L). on pain intensity, uterine artery doppler flow, and quality of life in primary dysmenorrhea: A double-blind, randomized controlled trialBanu T et al. (2025)
Pre-workouts with Juniper berry
No products found with this ingredient
We keep the dosages and values on this page as accurate as possible based on selected studies. New research may change these values. Nothing on this page is medical advice. If you have any doubts, always consult a doctor.