How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Blackcurrant
Blackcurrant extract has a small effect on endurance performance in a meta-analysis of 9 trials, and slightly increases fat burning during exercise. However, several trials find nothing.
Benefits
- Athletic performance: a meta-analysis of 9 trials finds a small but significant effect (0.45), with 105 to 210 mg of blackcurrant anthocyanins before exercise.
- Cycling: 7 days at 300 mg of extract per day improved a 16.1 km time trial by 2.4% in 14 cyclists.
- Repeated sprints: 10.6% more total distance in intense intermittent running in 13 men, after 7 days at 300 mg per day.
- Climbing: 23% more climbing time in 18 climbers, after 7 days at 600 mg per day.
- Fat burning during exercise: a meta-analysis of 15 studies and 226 participants finds increased fat utilization and decreased carbohydrate utilization during exercise; 27% more fat burned in 16 trained women at 600 mg per day.
- Recovery: in 27 adults, 3 g per day before and after eccentric exercise accelerated the return of strength and reduced muscle soreness at 24 and 48 hours.
- Blood glucose: in 25 overweight individuals, 8 days at 600 mg per day improved insulin sensitivity by 22%; in 23 adults, a beverage rich in extract before a sugary meal reduced the glucose spike.
- Glaucoma: in addition to treatment, 50 mg of blackcurrant anthocyanins per day for 2 years slowed the degradation of the visual field in 38 patients.
Precautions
Side effects: the meta-analysis reports no known side effects, but too few trials report them to conclude. Limitations: several trials find nothing: neither in cycling among 16 trained cyclists (single dose or 7 days), nor on a 2,000 m row among 9 rowers, nor in intense running among 15 men. Recovery: no effect on jump performance, muscle soreness or fatigue after a half-marathon among 20 runners; the nectar reduced blood markers of muscle damage, but not pain. Weight training strength: a trial on 20 adults finds increased strength in the bench press and leg press, but the authors do not rule out a placebo effect. Elderly people: in 14 elderly adults, blood pressure decreased over 7 days, but nothing changed regarding walking or cognition. Small trials: from 9 to 27 participants, mostly over one week; the effect on fat burning varies according to training, sex, dose and duration.
Recommended dosage
Trials: 300 to 600 mg of extract per day for 7 days (105 to 210 mg of anthocyanins), or 900 mg as a single dose 2 hours before exercise.
How to take it
- Dose: the meta-analysis places the effective dose between 105 and 210 mg of anthocyanins before exercise, i.e., 300 to 600 mg of extract in the trials.
- Duration: most trials give the extract 7 days before the test; on blood glucose, a single dose did nothing, whereas 8 days worked.
- More is not necessarily better: 600 and 900 mg per day yielded almost the same increase in fat burning (21.5% and 24.1%).
- Single dose: 900 mg taken 2 hours before a 5 km run improved the time of 16 trained runners.
- Form: almost all trials use New Zealand blackcurrant extract in capsules; one trial provided blackcurrant nectar twice a day for 8 days.
- With caffeine: no additional benefit in two trials, one in intermittent running, the other in cycling.
Did you know?
In 12 men running for one hour in the heat, 92% experienced digestive issues (burping, stitch in the side) under placebo, compared to 25% after 7 days of blackcurrant extract.
What the studies say
This systematic review and meta-analysis indicates that blackcurrant extract supplementation can increase fat oxidation and decrease carbohydrate oxidation during exercise in active adults. However, results may vary depending on individual factors such as training status, sex, dose, and duration of intake.
Cook MD, Bateman JJ, Willems MET. — Journal of dietary supplements (2026) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more