Pterostilbene

Pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene)  is a stilbenoid chemically related to resveratrol. In plants, it serves a defensive phytoalexin role.

Natural occurrence
Pterostilbene is found in almonds, various Vaccinium berries (including blueberries ), grape leaves and vines, and Pterocarpus marsupium heartwood.

Safety and regulation
Pterostilbene is considered to be a corrosive substance, is dangerous upon exposure to the eyes, and is an environmental toxin, especially to aquatic life. A preliminary study of healthy human subjects given pterostilbene for 6–8 weeks, showed pterostilbene to be safe for human use at dosages up to 250 mg per day, although this study did not assess metabolic effects on the lipid profile.

Other studies have reported dose-based elevations of low density lipoprotein cholesterol (LDL-C, "bad cholesterol") and decreased high density lipoprotein cholesterol (HDL-C, "good cholesterol") within 4 to 8 weeks of daily dosing. The elevation of LDL-C may move previously normal ranges into borderline high or high reference range and has raised questions about the longterm cardiovascular risk of pterostilbene supplementation in humans.

Its chemical relative, resveratrol, received FDA GRAS status in 2007, and approval of synthetic resveratrol as a safe compound by the European Food Safety Authority (EFSA) in 2016. Pterostilbene differs from resveratrol by exhibiting increased bioavailability (80% compared to 20% in resveratrol) due to the presence of two methoxy groups which cause it to exhibit increased lipophilic and oral absorption.

Research
Pterostilbene is being studied in laboratory and preliminary clinical research.