NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated August 1, 2026

Supplement × Supplement·Evidence index

L-Arginine and Pine Bark Extract: what the published research says

PubMed indexes 8 records that name L-Arginine and Pine Bark Extract together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.

Read this first

An evidence index, not guidance.

Every statement below is attributed to a named, dated, linked source.

This page lists published research relevant to L-Arginine and Pine Bark Extract. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.

The research

8 studies naming L-Arginine and Pine Bark Extract.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Efficacy of L-arginine and Pycnogenol ® in the treatment of male erectile dysfunction: a systematic review and meta-analysis.

Frontiers in endocrinology · 2023 · PMID 37908749

Meta-AnalysisSystematic ReviewHuman subjects

“These results indicate that the combination of PAL may have a significant effect on improving sexual function in patients with mild to moderate ED. This study will provide clinicians with more options for treating patients with ED. More randomized controlled trials are needed in the future to further demonstrate the effect of combination therapy on sexual function in patients with ED.”

Tian et al. · Authors' conclusion

Names both L-Arginine and Pine Bark Extract in its title.

Clinical assessment of a supplement of Pycnogenol® and L-arginine in Japanese patients with mild to moderate erectile dysfunction.

Phytotherapy research : PTR · 2012 · PMID 21618639

Clinical Trial

“No adverse reactions were observed during the study period. In conclusion, Pycnogenol® in combination with L-arginine as a dietary supplement is effective and safe in Japanese patients with mild to moderate erectile dysfunction.”

Aoki et al. · From the abstract

Names both L-Arginine and Pine Bark Extract in its title.

Treatment of erectile dysfunction with pycnogenol and L-arginine.

Journal of sex & marital therapy · 2003 · PMID 12851125

Clinical Trial

“Finally, after the third month of treatment, 92.5% of the men experienced a normal erection. We conclude that oral administration of L-arginine in combination with Pycnogenol causes a significant improvement in sexual function in men with ED without any side effects.”

Stanislavov et al. · From the abstract

Names both L-Arginine and Pine Bark Extract in its title.

Enzymes Involved in the Biosynthesis of Arginine from Ornithine in Maritime Pine (Pinus pinaster Ait.).

Plants (Basel, Switzerland) · 2020 · PMID 32992504

“In this work, recombinant PpOTC, PpASSY and PpASL enzymes from maritime pine (Pinus pinaster Ait.) were produced in Escherichia coli to enable study of their molecular and kinetics properties. The results reported here provide a molecular basis for the regulation of arginine and ornithine metabolism at the enzymatic level, suggesting that the reaction catalyzed by OTC is a regulatory target in the homeostasis of ornithine pools that can be either used for the biosynthesis of…”

Urbano-Gámez et al. · From the abstract

Names both L-Arginine and Pine Bark Extract in its title.

The role of arginine metabolic pathway during embryogenesis and germination in maritime pine (Pinus pinaster Ait.).

Tree physiology · 2018 · PMID 29112758

“By contrast, enhanced expression levels were only observed during the last stages of maturation and germination of ZE, consistent with the adequate accumulation and mobilization of protein reserves. These results suggest that arginine metabolism is unbalanced in SE (simultaneous biosynthesis and degradation of arginine) and could explain the lower accumulation of storage proteins observed during the late stages of somatic embryogenesis.”

Llebrés et al. · From the abstract

Names both L-Arginine and Pine Bark Extract in its title.

Improvement of seminal quality and sexual function of men with oligoasthenoteratozoospermia syndrome following supplementation with L-arginine and Pycnogenol®.

Archivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica · 2015 · PMID 26428638

Human subjects

“L-arginine acts to increase the production of nitric oxide and Pycnogenol(®) activates the endothelial nitric oxide synthase and it is a potent antioxidant and inhibitor of inducible nitric oxide synthase. This study suggests that the combination of Pycnogenol(®) and L-arginine (Edicare(®)) is helpful for infertile men to ameliorate simultaneously quality of sperms as well as erectile functions.”

Kobori et al. · From the abstract

Names both L-Arginine and Pine Bark Extract in its title.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

NutriStack

Track what you actually take.

NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers L-Arginine, Pine Bark Extract, and several hundred other substances.

The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.