Pterostilbene — Research Profile

For practical supplementation, pterostilbene has a significant advantage: ~80% oral bioavailability compared to <1% for resveratrol. This means a 50mg dose of pterostilbene achieves greater tissue exposure than a 500mg dose of resveratrol. Both activate SIRT1 and AMPK. The main caveat is that resveratrol has far more published human clinical trials. Many longevity practitioners now prefer pterostilbene or use both together.

In the Riche et al. (2014) trial, the highest dose (250mg twice daily) was associated with increased LDL cholesterol in some participants. Lower doses (50-125mg) did not show this effect. If you have elevated LDL, start at a lower dose and monitor your lipid panel. The clinical significance of this finding is still debated.

Blueberries contain pterostilbene but in very small amounts — approximately 99μg per cup. To reach a supplemental dose of 100mg, you would need over 1000 cups of blueberries daily. Supplementation is necessary for therapeutic doses, though eating blueberries provides many other health-promoting compounds.

Pterostilbene is the dimethylated form of resveratrol, and its methyl groups give it much greater oral bioavailability, about 80% versus roughly 20% for resveratrol in comparative animal pharmacokinetics. Human trials have used both purified trans-pterostilbene and a Pterocarpus marsupium extract standardized to over 90% pterostilbene, with no head-to-head comparison establishing one as superior. Because pterostilbene is already well absorbed, no specialized delivery form has been shown to be necessary.

Robust human evidence is limited, and most positive trials tested pterostilbene combined with nicotinamide riboside rather than pterostilbene alone. In that combination it raised NAD+ levels in older adults and produced time-dependent drops in the liver enzymes ALT and GGT in fatty-liver patients, though it failed to improve muscle recovery after injury and did not meet the primary endpoint in the liver trial. Standalone anti-aging and cognitive benefits remain preclinical, having been shown in aging mice but not confirmed in humans.

Human trials have used roughly 100-250 mg per day. The main safety study tested 100 mg/day and 250 mg/day in people with high cholesterol, a standardized Pterocarpus marsupium extract used 200 mg/day, and NRPT products supply about 200 mg pterostilbene daily. No optimal or minimum effective standalone dose has been established, so these trial amounts are the practical reference range rather than a proven target.

Time of day has not been directly studied for pterostilbene. Clinical trials simply split the dose and gave it twice daily without specifying morning versus evening or tying it to meals, and no study has compared one schedule against another. There is therefore no evidence-based reason to prefer a particular time; twice-daily dosing is the only pattern that has been formally tested.

In short human trials, adverse effects were uncommon. The 6-8 week study at up to 250 mg/day reported no statistically significant self-reported or major adverse reactions and no abnormalities on liver, kidney, or glucose testing, and a separate 2-month study at 200 mg/day recorded no serious adverse events with hematology, lipid, glycemic, thyroid, and liver and kidney panels all staying in the normal range. Because trials were short and modest in size, uncommon or longer-term side effects cannot be ruled out.

No clinical drug-interaction studies exist, but laboratory work signals a plausible risk. In vitro, pterostilbene inhibited the drug-metabolizing enzyme CYP2C8 (IC50 around 3.0 microM) and UGT1A6 (IC50 about 15.1 microM), while showing no meaningful inhibition of CYP3A4. This suggests it could theoretically raise levels of drugs cleared by CYP2C8 (for example pioglitazone or repaglinide), though the authors stress the real-world relevance is unconfirmed and warrants clinical study.

The evidence base is thin, and the strongest human signal is in adults with non-alcoholic fatty liver disease, where pterostilbene with nicotinamide riboside lowered liver enzymes, though it missed its primary endpoint. There is no established role for the general population, and people taking medications cleared by CYP2C8 should be cautious given the in vitro enzyme inhibition. Pregnant or breastfeeding individuals lack any safety data and should avoid it.

There is no established onset for pterostilbene taken on its own, and the answer depends entirely on the endpoint. In the main human trials it is paired with nicotinamide riboside (NRPT), where blood NAD+ rose roughly 40-90% within 4 weeks and held through 8 weeks, while liver-enzyme improvements in fatty-liver patients emerged only over a 6-month course. Most standalone benefits attributed to pterostilbene come from animal work, so no reliable human timeline exists for effects like cognition or metabolism.

Human safety data extend to about 6 months at most. A 6-8 week trial in 80 people with high cholesterol found no adverse effects on liver, kidney, or glucose markers at up to 250 mg/day, and a 2-month trial of a Pterocarpus marsupium extract standardized to over 90% pterostilbene (200 mg/day) reported normal blood work and no serious adverse events. The longest study, a 6-month NAFLD trial of pterostilbene with nicotinamide riboside, judged the combination safe, but daily use beyond six months has not been formally evaluated.

No tolerable upper limit or toxicity threshold has been set for pterostilbene. The available human safety analysis concluded it is generally safe up to 250 mg/day over 6-8 weeks, with no drug reactions detected on liver, kidney, or glucose testing, but doses higher than roughly 250 mg/day have not been studied in people. Because there is no data above that level, exceeding the doses used in trials means moving beyond what has actually been tested for safety.

Most human pterostilbene research has actually used it in combination, most often with nicotinamide riboside (marketed as NRPT/Basis), typically about 200 mg pterostilbene alongside 1,000 mg nicotinamide riboside, a pairing that raised NAD+ levels and was tolerated in trials. It has also been delivered as a standardized Pterocarpus marsupium extract without added supplements. No study has reported a harmful supplement-supplement interaction, but combinations beyond the NR pairing have not been formally tested.

Prefer the trans-pterostilbene isomer, which is the naturally predominant, lipid-soluble form of the molecule, supplied either as purified pterostilbene or as a Pterocarpus marsupium extract standardized to over 90% pterostilbene (a form given at 200 mg/day for two months with no serious adverse events). Human trial doses cluster in the 100-250 mg/day range, so a label stating the exact pterostilbene content per serving helps you stay within tested amounts. There is no official pharmacopeial standard for pterostilbene, so third-party purity testing is worth prioritizing.