100–200 mg/day.
Randomized placebo-controlled trial (61 children, 4 weeks): Pycnogenol (1 mg/kg/day) improved ADHD symptoms, which returned when it was stopped. Small study; promising signal to be confirmed.
View the study (study) →⏱ 3 min read
Pycnogenol (a registered trademark for a specific extract of the bark of Pinus pinaster, the French maritime pine that grows in the Landes region of France) is a patented extract standardized to oligomeric proanthocyanidins (OPC) and other polyphenols, marketed and clinically studied for more than 30 years, with a remarkably broad body of clinical evidence for multiple indications: chronic venous insufficiency, mild hypertension, erectile dysfunction, joint health, cognitive function, eye health, and others; it is one of the botanical extracts with the most published clinical trials per gram of real marketing, a feature that distinguishes it from many commercial products with less clinical backing.
The chemical composition includes oligomeric proanthocyanidins (with a profile similar to, but not identical to, that of grape seed extract), phenolic acids (caffeic, ferulic, p-coumaric), and other minor polyphenols; the documented pharmacological profile combines notable in vitro antioxidant activity, a mild antiplatelet effect, improved endothelial function, modulation of vascular nitric oxide release, and anti-inflammatory properties documented in several experimental models and in clinical studies.
The indication with the strongest clinical support is chronic venous insufficiency of the lower limbs: several trials have documented significant reductions in edema, heaviness, and other symptoms at doses of 100-300 milligrams daily for 4-8 weeks, with magnitudes comparable to those of some pharmacological venoactive drugs and with a favorable tolerability profile.
In mild hypertension and prehypertension, several studies have documented modest reductions in systolic and diastolic blood pressure (4-10 mmHg) with supplementation at 100-200 mg/day for 8-12 weeks, along with improvements in endothelial function documented by flow-mediated dilation and other markers; these effects are consistent with the NO-modulating mechanism and with moderate clinical support.
In mild erectile dysfunction, several trials have documented significant improvements with doses of 60-120 mg/day for 8-12 weeks, especially in formulations combined with L-arginine (which provides the substrate for the synthesis of nitric oxide, whose vasodilation is essential for erection); the magnitude is modest compared with pharmaceutical PDE-5 inhibitors but useful as a first-line option in mild dysfunction.
In symptomatic osteoarthritis (especially of the knee), several studies have shown significant improvements in pain and function scales with supplementation at 100-150 mg/day for 12 weeks; the effects are quantitatively smaller than those of pharmacological anti-inflammatories but with a significantly better tolerability profile.
In healthy adults and especially in older adults, several studies have documented modest improvements in processing speed, attention, and memory with supplementation at 100-150 mg/day for 8-12 weeks; the data are interesting and consistent with the profile of improved microcirculation.
In premenstrual syndrome, dysmenorrhea, diabetic retinopathy, allergic asthma, and attention-deficit/hyperactivity disorder (ADHD) in children, there are preliminary clinical data with varying degrees of support that place Pycnogenol as an extract with an unusually broad clinical profile for a botanical intervention.
The doses studied range from 60 to 360 milligrams daily depending on the indication, divided into one or two doses with or without food; the commercial product is the specific Pycnogenol from Horphag Research (a registered trademark with exclusive right of use), although generic "French maritime pine extracts" exist on the market with potentially similar composition but without the backing of the specific published clinical trials; the effect on vascular and cognitive indications appears gradually and requires at least 4-8 weeks to evaluate.
Generally well tolerated; the adverse effects described are rare and mild (digestive discomfort, headache, occasionally itching); people taking anticoagulants should use caution because of the mild antiplatelet effect described, which could increase the risk of bleeding; those taking antihypertensives may have a mild potentiation of the hypotensive effect; people with active autoimmune diseases should exercise theoretical caution; in pregnancy and breastfeeding the data are limited and avoidance is recommended as a precaution; people who are going to undergo surgery should stop Pycnogenol at least 1-2 weeks beforehand; generic products without the registered trademark may have a different composition profile and clinical efficacy that is not necessarily equivalent to that of the specific Pycnogenol studied clinically; the cost per gram of Pycnogenol is significantly higher than that of grape seed extract (with a partially similar composition), and the choice between the two depends on the balance of cost and clinical support for the specific indication.
Information, not medical advice. Scientific evidence reflects the quality of the studies.