Maritime Pine

Maritime pine was the pine most often tapped for resin in Spain, where the industry ran from the 1840s until low prices ended it in the 1970s. Resin became one of the country’s most important non-timber forest products, and trees scarred by tapping are still common there ^{1Reference 1Earle · 2023Pinus pinaster — species description, distribution, subspecies and conservation status — reference databaseView study →}.

In a double-blind RCT, 40 people with chronic venous insufficiency took 100 mg of the extract three times a day or placebo for two months. The extract significantly reduced edema, leg heaviness and pain, and about 60% of treated patients lost their edema and pain completely. The placebo group showed no change, and venous blood flow did not change in either group ^{13Reference 13Arcangeli P · 2000RCTPycnogenol in chronic venous insufficiency — randomised placebo-controlledView study →}.

A review from the manufacturer’s research arm collects further trials in venous insufficiency, flight-related leg edema, venous ulcers and hemorrhoids ^{14Reference 14Gulati OP · 2014ReviewPycnogenol® in chronic venous insufficiency and related venous disorders — reviewView study →}. The Cochrane review included two venous trials with 60 participants and rated the pain and treatment-efficacy findings very low certainty ^{3Reference 3Robertson NU et al. · 2020Systematic reviewPine bark (Pinus spp.) extract for treating chronic disorders — systematic review of 27 RCTs, 1,641 participantsView study →}.

A 2025 meta-analysis of newer venous drugs found benefit from the extract for pain and skin blood flow, with less consistent effects on edema ^{6Reference 6Miguel CB et al. · 2025Meta-analysisEmerging pharmacological interventions for chronic venous insufficiency: systematic review and meta-analysis — meta-analysisView study →}.

Gap: trials are small, short and mostly industry-sponsored. No large independent trial or comparison with compression has been run.

A 2019 meta-analysis of 24 RCTs (1,594 participants) found small falls in systolic (−2.5 mmHg) and diastolic (−1.8 mmHg) blood pressure, with lower fasting glucose, HbA1c, BMI and LDL and higher HDL ^{7Reference 7Malekahmadi M et al. · 2019Meta-analysisEffects of pycnogenol on cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →}.

A 2025 meta-analysis of 27 RCTs found similar falls in blood pressure, fasting glucose, HbA1c, body weight and LDL, but no change in BMI or HDL ^{8Reference 8Mohammadi S et al. · 2025Meta-analysisDoes supplementation with pine bark extract improve cardiometabolic risk factors? A systematic review and meta-analysis — meta-analysisView study →}.

A blood-pressure meta-analysis of 12 trials found a diastolic effect only in trials longer than 12 weeks ^{9Reference 9Pourmasoumi M et al. · 2020Meta-analysisEffect of pycnogenol supplementation on blood pressure: a systematic review and meta-analysis of clinical trials — meta-analysisView study →}.

⚠ A meta-analysis restricted to seven double-blind, placebo-controlled trials (626 participants) found no significant change in blood pressure ^{10Reference 10Fogacci F et al. · 2020Meta-analysisEffect of Pycnogenol on blood pressure: findings from a PRISMA compliant systematic review and meta-analysis of randomized, double-blind, placebo-controlled clinical studies — meta-analysisView study →}.

Two lipid meta-analyses found no change in total or LDL cholesterol; one found a small rise in HDL ^{11,12Reference 11Sahebkar A · 2014Meta-analysisA systematic review and meta-analysis of the effects of pycnogenol on plasma lipids — meta-analysisView study →Reference 12Hadi A et al. · 2019Meta-analysisThe impact of pycnogenol supplementation on plasma lipids in humans: a systematic review and meta-analysis of clinical trials — meta-analysisView study →}.

The bark’s procyanidins scavenge free radicals, and in cell studies the extract doubled the synthesis of antioxidant enzymes ^{2Reference 2Rohdewald P · 2002ReviewA review of the French maritime pine bark extract (Pycnogenol), a herbal medication with a diverse clinical pharmacology — reviewView study →}.

Taken by mouth, it reduced UV-induced skin reddening in a clinical study ^{2Reference 2Rohdewald P · 2002ReviewA review of the French maritime pine bark extract (Pycnogenol), a herbal medication with a diverse clinical pharmacology — reviewView study →}. Later work reports effects on skin pigmentation, barrier function and the skin’s extracellular matrix ^{30Reference 30Grether-Beck S et al. · 2016ReviewFrench maritime pine bark extract (Pycnogenol®) effects on human skin: clinical and molecular evidence — reviewView study →}.

In a 12-week registry study of healthy professionals, 150 mg/day lowered plasma free radicals by about 30%, with no change in controls ^{24Reference 24Belcaro G et al. · 2014Clinical trialPycnogenol® improves cognitive function, attention, mental performance and specific professional skills in healthy professionals aged 35-55 — clinical trialView study →}.

Gap: these biomarker changes have not been linked to a clinical outcome.

A double-blind RCT in 77 people with type 2 diabetes found that 100 mg a day for 12 weeks, alongside standard treatment, lowered plasma glucose against placebo. HbA1c also fell, but the difference from placebo was significant only in the first month ^{17Reference 17Liu X et al. · 2004RCTAntidiabetic effect of Pycnogenol French maritime pine bark extract in patients with diabetes type II — randomised placebo-controlledView study →}.

In 46 people with type 2 diabetes and microalbuminuria, 100 mg a day for eight weeks lowered HbA1c, total cholesterol and urinary albumin. Fasting glucose did not change significantly ^{18Reference 18Navval-Esfahlan E et al. · 2021RCTEffect of French maritime pine bark extract supplementation on metabolic status and serum vascular cell adhesion molecule-1 levels in patients with type 2 diabetes and microalbuminuria — randomised controlled trialView study →}.

The pooled analyses found small reductions in fasting glucose and HbA1c ^{7,8Reference 7Malekahmadi M et al. · 2019Meta-analysisEffects of pycnogenol on cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →Reference 8Mohammadi S et al. · 2025Meta-analysisDoes supplementation with pine bark extract improve cardiometabolic risk factors? A systematic review and meta-analysis — meta-analysisView study →}.

A laboratory-made ethanol extract of pine bark, not the standardised extract, inhibited α-glucosidase and α-amylase and blunted blood-sugar rises in diabetic mice ^{19Reference 19Kim YM et al. · 2005In vitroInhibitory effect of pine extract on alpha-glucosidase activity and postprandial hyperglycemia — in vitroView study →}.

Gap: the trials are short add-on studies of 12 weeks or less, with no hard endpoints and no trial of the extract used alone.

In human cartilage cells and joint-lining cells, the extract blocked urate-crystal-induced COX-2, IL-8 and iNOS and the activation of NF-κB. In rats it reduced joint inflammation after urate crystals were injected into the joint ^{27Reference 27Peng YJ et al. · 2012AnimalPycnogenol attenuates the inflammatory and nitrosative stress on joint inflammation induced by urate crystals — animal modelView study →}.

The extract inhibits 5-lipoxygenase expression and lowers leukotriene levels in people with asthma ^{29Reference 29Belcaro G et al. · 2011Clinical trialPycnogenol® improvements in asthma management — controlled clinical study, n=76View study →}.

In a double-blind crossover trial in 26 people with asthma, 22 completed, almost all responded favourably to the extract, and serum leukotrienes fell against placebo ^{28Reference 28Hosseini S et al. · 2001RCTPycnogenol® in the management of asthma — randomised placebo-controlledView study →}.

In a six-month controlled study of 76 people with allergic asthma on inhaled steroids, 55% of those adding 100 mg/day of the extract moved to a lower steroid dose, against 6% of those on steroids alone ^{29Reference 29Belcaro G et al. · 2011Clinical trialPycnogenol® improvements in asthma management — controlled clinical study, n=76View study →}.

Gap: the human evidence is these asthma studies. The joint work is cell and animal only.

In an RCT in 46 people with early diabetic retinopathy, three months of the extract improved retinal edema, retinal thickness and blood flow in the central retinal artery. Visual acuity improved from 14/20 to 17/20, with no change in the placebo group ^{15Reference 15Steigerwalt R et al. · 2009RCTPycnogenol improves microcirculation, retinal edema, and visual acuity in early diabetic retinopathy — randomised controlled trialView study →}.

A review of five trials with 1,289 patients, run since the late 1960s and mostly published in French or German, reported slower progression of retinopathy. One trial was controlled against calcium dobesilate and one against placebo ^{16Reference 16Schönlau F · 2001ReviewPycnogenol for diabetic retinopathy: a review — reviewView study →}.

Gap: the trials are small or old, and several predate modern retinopathy treatment.

A 2023 meta-analysis of three trials (184 men) found that the extract combined with L-arginine improved erectile function, satisfaction, orgasmic function and desire scores. Testosterone did not change ^{20Reference 20Tian Y et al. · 2023Meta-analysisEfficacy of L-arginine and Pycnogenol® in the treatment of male erectile dysfunction: a systematic review and meta-analysis — meta-analysisView study →}.

In one of those trials, 40 men took 1.7 g/day of L-arginine for a month, and 2 had a normal erection. Adding 80 mg/day of the extract in the second month raised that to 80%, and 120 mg/day in the third month to 92.5% ^{21Reference 21Stanislavov R · 2003Clinical trialTreatment of erectile dysfunction with pycnogenol and L-arginine — clinical trialView study →}.

One placebo-controlled trial tested the extract alone. In 53 men with erectile dysfunction, three months of the extract improved erectile-function scores by 45% in those with diabetes and 22% in those without, and lowered total and LDL cholesterol in the diabetic group ^{22Reference 22Trebaticky B et al. · 2019RCTNatural polyphenols improve erectile function and lipid profile in patients suffering from erectile dysfunction — randomised controlled trialView study →}.

Gap: the combination trials cannot separate the extract’s effect from that of L-arginine ^{20,21Reference 20Tian Y et al. · 2023Meta-analysisEfficacy of L-arginine and Pycnogenol® in the treatment of male erectile dysfunction: a systematic review and meta-analysis — meta-analysisView study →Reference 21Stanislavov R · 2003Clinical trialTreatment of erectile dysfunction with pycnogenol and L-arginine — clinical trialView study →}.

In an 8-week study, 53 healthy students taking the extract improved on tests of sustained attention, memory and executive function against a comparison group. They also failed fewer university exams (6.25% against 10.71%) ^{23Reference 23Luzzi R et al. · 2011Clinical trialPycnogenol® supplementation improves cognitive function, attention and mental performance in students — clinical trialView study →}.

In a 12-week registry study, 30 professionals aged 35–55 taking 150 mg/day improved on several cognitive tests and on mood against 29 controls ^{24Reference 24Belcaro G et al. · 2014Clinical trialPycnogenol® improves cognitive function, attention, mental performance and specific professional skills in healthy professionals aged 35-55 — clinical trialView study →}.

In a network meta-analysis of antioxidant treatments for children and adolescents with ADHD, pycnogenol ranked among the most effective for attention on parent and teacher rating scales. The authors noted the low quality of the included studies ^{25Reference 25Zhou P et al. · 2024Meta-analysisSafety and efficacy of antioxidant therapy in children and adolescents with attention deficit hyperactivity disorder: a systematic review and network meta-analysis — systematic reviewView study →}. The one ADHD trial in the Cochrane review (61 children) gave very low-certainty evidence ^{3Reference 3Robertson NU et al. · 2020Systematic reviewPine bark (Pinus spp.) extract for treating chronic disorders — systematic review of 27 RCTs, 1,641 participantsView study →}.

Gap: both cognition studies were open comparisons rather than blinded randomised trials ^{23,24Reference 23Luzzi R et al. · 2011Clinical trialPycnogenol® supplementation improves cognitive function, attention and mental performance in students — clinical trialView study →Reference 24Belcaro G et al. · 2014Clinical trialPycnogenol® improves cognitive function, attention, mental performance and specific professional skills in healthy professionals aged 35-55 — clinical trialView study →}.

A meta-analysis of 69 trials of dietary supplements for osteoarthritis listed pycnogenol among seven supplements with large, clinically important effects on pain in the short term. The overall quality of the evidence was very low ^{26Reference 26Liu X et al. · 2018Meta-analysisDietary supplements for treating osteoarthritis: a systematic review and meta-analysis — meta-analysisView study →}.

The one knee osteoarthritis trial pooled by Cochrane (37 participants) reported better WOMAC scores and less use of anti-inflammatory painkillers, at very low certainty ^{3Reference 3Robertson NU et al. · 2020Systematic reviewPine bark (Pinus spp.) extract for treating chronic disorders — systematic review of 27 RCTs, 1,641 participantsView study →}.

In rats, the extract reduced joint inflammation caused by urate crystals ^{27Reference 27Peng YJ et al. · 2012AnimalPycnogenol attenuates the inflammatory and nitrosative stress on joint inflammation induced by urate crystals — animal modelView study →}.

Gap: there is no large independent trial.

Side effects. Across the trials, unwanted effects were mild and occurred in a small percentage of people, mostly as stomach discomfort ^{2,16Reference 2Rohdewald P · 2002ReviewA review of the French maritime pine bark extract (Pycnogenol), a herbal medication with a diverse clinical pharmacology — reviewView study →Reference 16Schönlau F · 2001ReviewPycnogenol for diabetic retinopathy: a review — reviewView study →}. In the 77-person diabetes trial, heart tracings, electrolytes and kidney markers did not change ^{17Reference 17Liu X et al. · 2004RCTAntidiabetic effect of Pycnogenol French maritime pine bark extract in patients with diabetes type II — randomised placebo-controlledView study →}.

Safety reporting. Most trials in the Cochrane review did not report serious adverse events or hospital admissions, so the safety record is incomplete ^{3Reference 3Robertson NU et al. · 2020Systematic reviewPine bark (Pinus spp.) extract for treating chronic disorders — systematic review of 27 RCTs, 1,641 participantsView study →}.

Pregnancy. In one small trial, women in the third trimester took 30 mg/day for back, hip, pelvic and leg pain until delivery, with no unwanted effects reported ^{31Reference 31Kohama et al. · 2006Clinical trialPycnogenol alleviates pain associated with pregnancy — controlled clinical study (third trimester, 30 mg/day)View study →}. That dose is below the range used in most trials.

Immune conditions. The extract has shown immune-modulating effects in animals and in patients with lupus ^{2Reference 2Rohdewald P · 2002ReviewA review of the French maritime pine bark extract (Pycnogenol), a herbal medication with a diverse clinical pharmacology — reviewView study →}. This is the basis of a caution sometimes given for autoimmune disease; no clinical problem has been reported.

Drug interactions. No drug-interaction study of the extract was found. It lowers glucose in people with diabetes and has a small effect on blood pressure, so blood sugar and blood pressure are worth watching alongside medicines for either ^{7,17Reference 7Malekahmadi M et al. · 2019Meta-analysisEffects of pycnogenol on cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials — meta-analysisView study →Reference 17Liu X et al. · 2004RCTAntidiabetic effect of Pycnogenol French maritime pine bark extract in patients with diabetes type II — randomised placebo-controlledView study →}.

Resin and turpentine. The tolerability record belongs to the purified bark extract. Concentrated resin and turpentine are gastrointestinal irritants when taken internally.