The case for
Pycnogenol
French maritime pine bark extract. 40 years of research. Six peer-reviewed clinical trials in endurance sport. Here is what the evidence shows — and why it is in every KPI capsule.
Join the waitlist →
One tree. One coastline.
One extract.
The extract comes from the bark alone — not the wood, not the needles. Trees are harvested sustainably during thinning cycles, the polyphenol profile standardised to the same specification every batch. That consistency is what makes clinical research reproducible and directly relevant to what goes in the capsule.
Blood flow is the constraint.
Pycnogenol moves it.
During hard exercise, the cardiovascular system is the rate-limiter. Oxygen reaches muscle via blood. How fast that delivery happens determines how long aerobic metabolism can sustain effort before lactic acid accumulates and power drops.
Nitric oxide (NO) signals blood vessels to dilate. Pycnogenol stimulates eNOS — the enzyme that produces NO from L-arginine in the cells lining blood vessel walls. More NO, wider vessels, more oxygen reaching working muscle.
After two weeks of Pycnogenol, endothelial NO production increased forearm blood flow by up to 46% above baseline. Placebo showed no change.
Nishioka et al., Hypertension Research, 2007 — 16 healthy volunteers, double-blind placebo-controlledblood flow increase
vascular effect
placebo-controlled
More oxygen in.
Less CO₂ out.
Improved blood flow means improved tissue perfusion — the actual gas exchange at the capillary level. Two clinical studies measured this directly using skin sensors on the legs after six weeks of supplementation.
More oxygen in, less CO₂ retained — the physiological signature of better aerobic efficiency. Relevant for any endurance event where the aerobic-anaerobic threshold determines how long you hold pace.
Pycnogenol also improves red blood cell membrane fluidity and reduces platelet aggregation, keeping blood viscosity within a healthy range throughout a long effort.
Exercise burns fuel.
It also generates damage.
Peak mitochondrial activity during hard exercise is accompanied by a proportional rise in free radical production. At sufficient intensity, oxidative stress damages muscle cell membranes — remnants have been detected in the bloodstream after intense efforts.
Pycnogenol raised the oxygen radical absorbance capacity (ORAC) of human blood by 40% following supplementation, and strengthened capillary walls across 17+ clinical trials — reducing micro-bleedings from repeated heavy training loads.
following supplementation
capillary wall strengthening
Three independent trials.
Consistent direction.
Endurance improvements have been tested in a treadmill study, a military fitness protocol, and a triathlon preparation study. All three showed measurable performance gains over placebo.
Treadmill endurance at 85% VO₂max increased by 21% after 30 days on Pycnogenol versus placebo.
Pavlovic P., California State University Chico, 1999 — double-blind crossover, recreational athletes(8 weeks)
(30 days)
time (4 weeks)
In the triathlon study — 60 athletes, 4 weeks — overall race time dropped 10% and post-effort oxidative stress was dramatically lower in the Pycnogenol group. Athletes reported reduced post-training pain and fatigue.
Cramp is a circulation problem.
Pycnogenol addresses it upstream.
Cramps are increasingly understood as a circulatory insufficiency — muscle unable to receive adequate oxygen and nutrients at high workloads. Improved blood flow delays the onset of that threshold.
Cramp frequency in competitive athletes fell from 8.6 episodes per week to 2.4. One week after stopping, frequencies did not significantly increase — suggesting lasting vascular adaptation, not an acute effect.
Pycnogenol is effective for reducing pain and cramps in training and retraining, increasing the efficiency of training programs in both normal subjects and competitive athletes.
Vinciguerra et al., Angiology, 2006Not a pre-workout.
A protocol that compounds.
Select a phase to see what is happening inside the body.
eNOS activation begins
Pycnogenol polyphenols begin accumulating in circulation. eNOS stimulation starts increasing NO production at the endothelial level.
Antioxidant capacity begins rising. ORAC values start shifting measurably within the first week.
Measurable blood flow increase
This is when clinical trials first document significant vasodilation. Forearm blood flow increased by up to 46% above baseline at week 2 in Nishioka et al.
Tissue perfusion improves. Muscle is receiving more oxygen per unit of cardiac output.
Cramp frequency drops. Endurance rises.
Athletes in the Vinciguerra trial recorded cramp pain scores falling by up to 87% at week 4. Endurance on treadmill testing increases significantly over placebo.
Post-training pain and perceived fatigue reduce. Recovery between sessions shortens.
Triathlon and fitness test improvements
The largest performance gains in the literature emerge at 4–8 weeks. Triathlon time dropped 10%. 2-mile run time dropped 11%. Sit-up count rose 23%.
Oxidative stress markers were dramatically lower in Pycnogenol groups versus control — structural antioxidant adaptation, not just acute buffering.
Precision over volume.
Every detail deliberate.
Two ingredients. No fillers, no proprietary blends. You know exactly what is in each capsule, exactly what the clinical evidence says, and exactly who supplies the raw materials.
500 units.
One protocol.
Cycle 01 ships August 2026. Join the waitlist for early access and first allocation.
Join the waitlist →- Nishioka K et al. Pycnogenol augments endothelium-dependent vasodilation in humans. Hypertens Res 30: 775-780, 2007.
- Pavlovic P. Improved endurance by use of antioxidants. Eur Bull Drug Res 7(2): 26-29, 1999.
- Vinciguerra G et al. Cramps and muscular pain: prevention with Pycnogenol. Angiology 57: 331-339, 2006.
- Vinciguerra G et al. Evaluation of supplementation with Pycnogenol on fitness in normal subjects and triathlon athletes. J Sports Med Phys Fitness 53(6): 644-654, 2013.
- Devaraj S et al. Supplementation with pine bark extract increases plasma antioxidant capacity. Lipids 37: 931-934, 2002.
- Belcaro G et al. Microcirculatory improvement with Pycnogenol. Angiology 56: 699-705, 2005.
- Sivonova M et al. The effect of Pycnogenol on erythrocyte membrane fluidity. Gen Physiol Biophys 23: 39-51, 2004.
Pycnogenol is a registered trademark of Horphag Research. These statements have not been evaluated by the European Food Safety Authority or the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary.