Benefits
Blood pressure and blood vessel function
A pooled analysis of 7 double-blind Pycnogenol trials with 626 people found no significant change in blood pressure. A wider 2025 analysis of 27 trials of pine bark extracts found small drops of about 2 mmHg. In a crossover trial in 23 adults with heart disease, 200 mg a day for 8 weeks improved blood vessel widening (flow-mediated dilation) without changing blood pressure.
Attention and concentration
In a placebo-controlled trial in 61 children with ADHD, 1 mg per kg a day for 4 weeks improved teacher and parent ratings of hyperactivity, attention and concentration, and the gains faded a month after stopping. An independent review rated this single trial very low certainty. It is not a replacement for medical care.
Endurance training and exercise recovery
In a registry study by one research group, men training for a triathlon who took 150 mg a day for 4 weeks improved their race time by 10.8 minutes versus 4.6 minutes in controls, with fewer cramps and a faster return of an oxidative stress marker to normal. At 100 mg a day, Army fitness test scores improved more than in controls. Neither part was described as randomized, blinded or placebo-controlled.
Skin elasticity and hydration
In a double-blind crossover trial in 76 outdoor workers in Beijing, 100 mg a day for 12 weeks improved skin elasticity and prevented the autumn drop in skin hydration, the rise in water loss and skin darkening seen on placebo. An earlier uncontrolled study in 20 postmenopausal women taking 75 mg a day found better hydration and elasticity, most in dry skin.
Blood sugar and HbA1c
A 2025 pooled analysis of 27 randomized trials of pine bark extracts found fasting blood sugar about 6 mg/dL lower and HbA1c about 0.3 points lower than control, with no change in insulin. An independent review rated the diabetes trials of pine bark extract very low certainty. Anyone taking glucose-lowering medicine should talk to their doctor first.
Knee joint comfort and mobility
In a double-blind trial in 100 adults with mild to moderate knee osteoarthritis, 150 mg a day for 3 months improved WOMAC scores and pain ratings compared with placebo, and the use of pain relievers fell on Pycnogenol while it rose on placebo. An independent review counted three such trials with 293 people and rated the evidence very low certainty.
Erectile function with L-arginine (Prelox)
In a double-blind crossover trial in 50 men with mild to moderate erectile dysfunction, a combination of Pycnogenol and L-arginine aspartate (Prelox) for 1 month improved erectile function scores and doubled intercourse frequency compared with placebo. The results are for the combination, not Pycnogenol alone, and an independent review rated these trials very low certainty.
Menopausal and menstrual comfort
In two double-blind trials in perimenopausal women (about 200 and 170 enrolled), 200 mg or 60 mg a day eased menopausal symptoms; at 60 mg, hot flashes and sleep problems improved more than with placebo. In 116 women, 60 mg a day lowered period pain and pain reliever use in those with painful periods, but not in women with mild period pain.
CRP and IL-6 inflammation markers
Results are mixed. A pooled analysis of 5 trials (324 adults) found lower CRP, but the drop came from three trials by one research group, two not described as randomized or blinded. Two double-blind trials at 200 mg/day (one of a different pine bark extract) found no change. In 91 adults after dental cleaning, 100 mg twice daily for 3 months (Horphag grant) ended with lower serum IL-6 than placebo, but IL-6 barely fell on Pycnogenol.
Oxidative stress markers
In the crossover trial in 23 adults with heart disease, 200 mg a day for 8 weeks lowered 15-F2t-isoprostane, a marker of oxidative damage, compared with placebo. In the 200 mg trial in perimenopausal women, antioxidant status in the blood rose. These are laboratory markers rather than health outcomes.
Mechanism of action
Blood vessel lining (endothelial) effects
In a 12-week trial in 58 adults with mild high blood pressure, Pycnogenol lowered endothelin-1, a vessel-narrowing signal, and raised a prostacyclin marker that widens vessels. In a crossover trial in adults with heart disease it improved flow-mediated dilation. These effects on the vessel lining are the proposed basis for its circulation results.
Antioxidant activity
Pycnogenol's procyanidins are antioxidants in laboratory tests. In people, 8 weeks at 200 mg a day lowered 15-F2t-isoprostane, a marker of oxidative damage, in a placebo-controlled crossover trial.
Inflammatory signaling
Laboratory studies suggest procyanidins can damp inflammatory signaling pathways. In people, results on blood inflammation markers such as CRP and IL-6 are mixed across trials.
Skin matrix gene activity
In skin biopsies from 20 postmenopausal women taking Pycnogenol for 12 weeks, activity of the gene for hyaluronic acid synthase-1, an enzyme that makes the skin's water-holding hyaluronic acid, rose significantly, with a smaller rise in collagen-related genes. This was an uncontrolled study.
Clinical trials
Systematic review and meta-analysis of randomized, double-blind, placebo-controlled trials of Pycnogenol. (Fogacci et al. 2020, Angiology)
7 trials with 626 participants.
No significant change in systolic or diastolic blood pressure, mean arterial pressure or pulse pressure, and the result held in sensitivity analyses. A 2025 analysis of pine bark extracts in general (Mohammadi) found small reductions of about 2 mmHg.
Randomized, placebo-controlled, double-blind trial: 1 mg per kg a day or placebo for 4 weeks, with follow-up 1 month after stopping. (Trebatická et al. 2006, Eur Child Adolesc Psychiatry)
61 children with ADHD.
Hyperactivity fell and attention, visual-motor coordination and concentration improved on Pycnogenol, with no improvement on placebo; symptoms returned a month after stopping. A Cochrane review rated this single small trial very low certainty.
Registry study in two parts comparing Pycnogenol users with controls; randomization, blinding and placebo are not described: 100 mg a day for 8 weeks with the Army Physical Fitness Test, and 150 mg a day for 4 weeks of triathlon training. (Vinciguerra et al. 2013, J Sports Med Phys Fitness)
147 adults in the fitness part (74 Pycnogenol, 73 controls); 54 triathletes who completed training (32 men on Pycnogenol, 22 controls).
Running time, push-ups and sit-ups improved more with Pycnogenol. Triathletes improved their time by 10.8 minutes versus 4.6 minutes in controls, with fewer cramps and less post-run pain, and an oxidative stress marker recovered faster.
Single-center, double-blind, randomized, placebo-controlled crossover study: 50 mg twice a day for 12 weeks, from spring to autumn. (Zhao et al. 2021, Skin Pharmacol Physiol)
76 Han Chinese adults working outdoors in Beijing.
Pycnogenol prevented the autumn decrease in skin hydration, the rise in transepidermal water loss and skin darkening, and improved gross elasticity and elastic recovery; these effects were not seen on placebo.
Uncontrolled 12-week study with skin measurements and biopsies before, during and after supplementation. (Marini et al. 2012, Skin Pharmacol Physiol)
20 healthy postmenopausal women.
Skin hydration and elasticity improved significantly, most in women with dry skin at the start, and skin gene activity for hyaluronic acid synthase-1 rose. With no placebo group, the role of seasonal or other changes cannot be ruled out.
Double-blind, placebo-controlled, randomized trial: 150 mg a day with meals or placebo for 3 months, with WOMAC questionnaires every 2 weeks. (Cisár et al. 2008, Phytother Res)
100 adults with stage I or II knee osteoarthritis.
WOMAC index and pain scores improved on Pycnogenol but not on placebo, and pain reliever use fell on Pycnogenol while it rose on placebo.
Randomized, double-blind, placebo-controlled crossover trial: 1 month of the combination or placebo, with sexual function recorded in diaries. (Stanislavov et al. 2008, Int J Impot Res)
50 men with mild to moderate erectile dysfunction.
The authors reported that erectile function returned to normal and intercourse frequency doubled on the combination; blood testosterone and sperm eNOS rose. The product combined two ingredients, so Pycnogenol's own share is unknown.
Double-blind, placebo-controlled trial: 30 mg twice a day or placebo for 3 months, scored with the Women's Health Questionnaire and Kupperman index. (Kohama et al. 2013, J Reprod Med)
170 perimenopausal women.
Hot flashes and sleep problems improved more than on placebo at 4 and 12 weeks, and the Kupperman symptom score fell 56% versus 39% on placebo. A large placebo effect was seen for most other symptoms.
Randomized, double-blind, placebo-controlled trial: 200 mg a day of Pycnogenol or placebo, with menopausal symptoms scored on the Women's Health Questionnaire and antioxidant status and routine blood tests checked. (Yang et al. 2007, Acta Obstet Gynecol Scand)
About 200 perimenopausal women enrolled; 155 completed.
The authors reported that all menopausal symptom areas improved, antioxidant status rose and the LDL/HDL ratio improved on Pycnogenol, with no side effects reported. The abstract does not give the size of the difference from placebo.