Pterostilbene: The Blueberry Stilbene and What Human Trials Found


Pterostilbene is a small plant molecule from the stilbene family, the same family as resveratrol. It turns up in a few kinds of blueberries, in grapes and in the heartwood of the Indian kino tree, and it is sold as a supplement on its own and paired with nicotinamide riboside, a form of vitamin B3. The most-quoted fact about it, that far more of it reaches the bloodstream than resveratrol, comes from a rat study. This page sets out what is known: how much is in food, what that rat study measured, what the small number of human trials found (including a rise in cholesterol), which results come only from animals and cells, and how much remains unknown.


Table of Contents

  1. A Close Chemical Relative of Resveratrol
  2. Where Pterostilbene Is Found in Food and Plants
  3. Absorption Measured in Rats
  4. The 2014 Blood Pressure and Cholesterol Trial
  5. What the Safety Reports Found
  6. Other Human Studies of Pterostilbene
  7. Supplements That Pair It With Nicotinamide Riboside
  8. Findings in Animals and Cells
  9. The Sirtuin Label and the Evidence Behind It
  10. What Is Not Known
  11. Key Research Papers
  12. Connections
  13. Featured Videos

A Close Chemical Relative of Resveratrol

Resveratrol and pterostilbene share the same skeleton: two ring-shaped halves joined by a short bridge. Chemists name resveratrol 3,5,4′-trihydroxy-trans-stilbene, meaning it carries three hydroxyl groups (an oxygen bonded to a hydrogen) at three positions on its rings. Pterostilbene is 3,5-dimethoxy-4′-hydroxy-trans-stilbene. Two of those three hydroxyl groups are capped with a methyl group, which turns them into methoxy groups. That is why researchers call pterostilbene the “dimethylether analog” or “dimethylated” form of resveratrol.

The change looks minor on paper, but it matters in the body. Hydroxyl groups are where the liver and gut attach sulfate and glucuronic acid tags so that a molecule can be cleared quickly. Resveratrol is known for exactly this problem: after it is swallowed, only low levels of the original molecule appear in the blood, because it is converted to those tagged forms so fast. With two of its three hydroxyl groups capped, pterostilbene offers fewer attachment points, and it is also more fat-soluble. Researchers expected both features to let more of it reach the bloodstream intact, and a rat study (below) was designed to test that idea.

The amount of stilbenes in a fruit is not fixed. The muscadine grape study described below found that stilbene levels differ between cultivars and from year to year, which its authors tie to changing environmental conditions and the stresses a vine meets in a given season.

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Where Pterostilbene Is Found in Food and Plants

Blueberries and their relatives. The most-cited measurement comes from a 2004 study by Rimando and colleagues, who used gas chromatography with mass spectrometry to analyze berries from 10 species of the Vaccinium genus collected in Mississippi, North Carolina, Oregon and Canada. Resveratrol turned up widely, at levels between 7 and 5,884 nanograms per gram of dry sample, with lingonberry the highest and comparable to grapes (6,471 nanograms per gram of dry sample). Pterostilbene was much more limited. The study reported it in two cultivars of rabbiteye blueberry (Vaccinium ashei) and in deerberry (Vaccinium stamineum), at 99 to 520 nanograms per gram of dry sample. Those figures are for freeze-dried berry material, not fresh fruit, and the abstract does not report pterostilbene in the other species tested.

The practical point is that pterostilbene is present in blueberries in trace amounts, measured in billionths of a gram per gram, and only in some kinds. The quantities used in human supplement trials (milligrams a day, see below) are far larger than these trace amounts. The Blueberries page covers the much larger amounts of anthocyanins and other compounds the fruit does provide.

Grapes. Muscadine grapes have been studied for their stilbene content. A study by Kambiranda and colleagues followed berries from 42 muscadine cultivars over three years (2013, 2014 and 2015) and measured four stilbenoids together: trans-piceid, trans-resveratrol, epsilon-viniferins and trans-pterostilbene. The combined total ranged from 1.73 micrograms per gram of fresh weight in the lowest cultivar to 270.20 micrograms per gram in the highest, and certain cultivars produced consistent levels year after year. The abstract reports the four compounds as a combined total, so it does not show how much of that was pterostilbene. More on grapes as a food is on the Grapes page.

The Indian kino tree. The word “pterostilbene” comes from Pterocarpus, a genus of tropical trees. A 1997 study identified pterostilbene as one of three important phenolic constituents of the heartwood of Pterocarpus marsupium, the Indian kino tree, along with marsupsin and pterosupin. Extracts of this heartwood are the source material for several of the human studies described below.

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Absorption Measured in Rats

The study behind the common statement that pterostilbene is “80% bioavailable” was a rat study, published in 2011 by Kapetanovic and colleagues at the United States National Cancer Institute. Rats received resveratrol or pterostilbene by stomach tube every day for 14 consecutive days, at doses chosen to deliver the same number of molecules of each compound (50 or 150 milligrams per kilogram of body weight per day for resveratrol, 56 or 168 milligrams per kilogram per day for pterostilbene). Two further groups received a single dose into a vein, which allowed the researchers to calculate what share of the swallowed dose reached the circulation.

The authors concluded that equal-molecule doses of pterostilbene may have greater biological activity in the body than resveratrol. That conclusion is about rats given large doses by tube. The abstract contains no human measurements, and the 80% figure is not a human bioavailability figure. No study read for this page measured the share of a swallowed pterostilbene dose that reaches the blood in people.

One human study did look at blood levels. In a 2005 study of healthy volunteers who took 450 milligrams of a Pterocarpus marsupium extract, pterostilbene levels in the blood rose, but they stayed about five-fold lower than the concentration that had blocked an inflammatory messenger in human blood cells in the laboratory. That study is described in more detail in the section on other human studies.

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The 2014 Blood Pressure and Cholesterol Trial

The main human trial of pterostilbene taken on its own was run at the University of Mississippi and published by Riche and colleagues in 2014. It was a prospective, randomized, double-blind, placebo-controlled study, registered as NCT01267227, that enrolled 80 adults with a total cholesterol of at least 200 milligrams per deciliter and/or a low-density lipoprotein (LDL) cholesterol of at least 100 milligrams per deciliter. Participants were divided into four groups for 6 to 8 weeks:

  1. pterostilbene 125 milligrams twice daily (the high dose);
  2. pterostilbene 50 milligrams twice daily;
  3. pterostilbene 50 milligrams plus grape extract 100 milligrams twice daily;
  4. a matching placebo twice daily.

The trial measured blood lipids, blood pressure and weight. Its findings ran in two directions.

Blood pressure fell. On the high dose, systolic blood pressure (the upper number) fell by 7.8 mmHg and diastolic blood pressure (the lower number) by 7.3 mmHg, and both changes were statistically significant.

Low-density lipoprotein cholesterol rose. Pterostilbene taken alone raised low-density lipoprotein cholesterol by 17.1 milligrams per deciliter (P = 0.001). This rise was not seen in the group that took pterostilbene with grape extract (P = 0.47). People who were already taking a cholesterol medication at the start appeared to have a smaller rise.

Weight changed slightly. Among the 51 participants who were not on cholesterol medication, pterostilbene was followed by a minor drop in body mass index of 0.62 kilograms per square meter.

The authors summarized their result in one line: pterostilbene increases low-density lipoprotein cholesterol and reduces blood pressure in adults. The trial was small and short, it enrolled people who already had raised cholesterol, and it measured blood markers rather than heart attacks or strokes, so it cannot show what either change means over years.

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What the Safety Reports Found

The same Mississippi trial published its safety findings separately, a year earlier, in 2013. That report describes the same 80 participants with high cholesterol, split equally across the same four groups for 6 to 8 weeks. Safety was tracked with blood tests and with what participants reported themselves.

The authors concluded that pterostilbene is generally safe for use in humans up to 250 milligrams a day. That conclusion is bounded by the trial itself: 80 people, at most 8 weeks, and doses no higher than the high-dose group received. The safety report’s abstract does not mention the rise in low-density lipoprotein cholesterol that the efficacy paper later reported from the same trial.

Two other small trials of pterostilbene alone, described in the next section, also reported no adverse events: the 2005 kino-tree extract study, and a 2025 pilot study in healthy men that ran for 12 weeks.

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Other Human Studies of Pterostilbene

A PubMed search for clinical trials of pterostilbene turns up few studies of the compound on its own. Besides the Mississippi trial, two stand out.

The 2005 kino-tree extract study. Hougee and colleagues first tested a Pterocarpus marsupium extract in the laboratory. In human blood cells stimulated to make the inflammatory messenger prostaglandin E2, the extract, pure pterostilbene and pure resveratrol all reduced its production; the half-maximal concentration was 1.0 micromolar for pterostilbene and 3.2 micromolar for resveratrol. In whole-blood tests the extract acted on the COX-2 enzyme and not on COX-1. The researchers then gave healthy volunteers 450 milligrams of the extract by mouth. It did not lower prostaglandin E2 production in their blood tested afterwards. Blood pterostilbene went up, but to levels about five-fold below the concentration that had worked in the laboratory. No changes in safety measures and no extract-related adverse events were seen. The authors described a dose-finding study as the next step.

The 2025 microRNA pilot study. A double-blind, placebo-controlled trial by Otsuka and colleagues in Japan gave 30 healthy men pterostilbene at 10 or 100 milligrams a day, or a placebo, for 12 weeks. The main measurements were blood chemistry and blood levels of microRNAs, short strands of genetic material that help switch genes up or down. Two microRNAs, miR-34a and miR-193b, rose very sharply in some participants from week 4 onward, which the authors read as a sign that some people may respond and others not. No adverse events were reported, and the study physician found no abnormalities. This was a pilot study of a laboratory marker; it did not measure any health outcome.

Beyond these, most human research involving pterostilbene has tested it in combination with nicotinamide riboside, described next. In those trials the two ingredients are always given together, so they cannot show what pterostilbene does by itself.

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Supplements That Pair It With Nicotinamide Riboside

Pterostilbene is also sold in a two-ingredient capsule with nicotinamide riboside, a vitamin B3 compound that the body uses to make nicotinamide adenine dinucleotide (NAD+), a molecule every cell uses to turn food into energy. The 2020 kidney study below explains the pairing: earlier laboratory and animal work pointed to raising nicotinamide adenine dinucleotide and boosting sirtuin enzymes as two strategies, and the authors describe pterostilbene as a sirtuin activator. Researchers abbreviate the combination as NRPT. Several of these trials include authors employed by the company that markets the combination, and the 2017 paper states that the company funded that trial. The site’s pages on nicotinamide adenine dinucleotide boosters and nicotinamide adenine dinucleotide and nicotinamide mononucleotide cover the vitamin side in depth.

Taken together, these trials show that the combination raises blood nicotinamide adenine dinucleotide and was well tolerated over periods of 2 days to 6 months. They do not show which ingredient caused any change, and the one trial with a hard functional endpoint (muscle recovery) found nothing.

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Findings in Animals and Cells

Much of what is written about pterostilbene comes from animal and laboratory studies. The results below are real findings, but each was measured in rodents or in cells, and none has been repeated as a clinical outcome in people.

The 2005 kino-tree study is a useful reminder of the gap between these results and people: the anti-inflammatory effect it found in the laboratory was not seen when volunteers took the extract, because their blood levels did not reach the laboratory concentration.

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The Sirtuin Label and the Evidence Behind It

Pterostilbene is often described as a “sirtuin activator,” and some trial authors use the same label; the 2020 kidney study called it a potent sirtuin activator found in blueberries. Sirtuins are a family of enzymes involved in how cells respond to stress and nutrient supply, and the background, including the long dispute over whether resveratrol activates them directly, is on the Sirtuin Activators page.

The evidence for pterostilbene specifically is thin. In the 2012 SAMP8 mouse study, which found memory benefits on pterostilbene, neither pterostilbene nor resveratrol increased sirtuin 1 expression or the downstream markers of sirtuin 1 activation. The authors instead linked the benefit to higher expression of a different regulator, peroxisome proliferator-activated receptor alpha, and to pterostilbene’s greater fat-solubility. None of the human trials read for this page measured sirtuin activity directly. The combination trials measured nicotinamide adenine dinucleotide, which comes from the nicotinamide riboside half of the capsule.

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What Is Not Known

The overall picture: a compound with striking results in rats and mice, a modest drop in blood pressure alongside a rise in low-density lipoprotein cholesterol in its one controlled efficacy trial, a short safety record with no adverse findings, and a set of combination trials whose main measured change, a rise in nicotinamide adenine dinucleotide, belongs to the other ingredient.

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Key Research Papers

  1. Riche DM, Riche KD, Blackshear CT, McEwen CL, Sherman JJ, Wofford MR, Griswold ME. Pterostilbene on metabolic parameters: a randomized, double-blind, and placebo-controlled trial. Evid Based Complement Alternat Med. 2014;2014:459165. PubMed PMID: 25057276
  2. Riche DM, McEwen CL, Riche KD, Sherman JJ, Wofford MR, Deschamp D, Griswold M. Analysis of safety from a human clinical trial with pterostilbene. J Toxicol. 2013;2013:463595. PubMed PMID: 23431291
  3. Kapetanovic IM, Muzzio M, Huang Z, Thompson TN, McCormick DL. Pharmacokinetics, oral bioavailability, and metabolic profile of resveratrol and its dimethylether analog, pterostilbene, in rats. Cancer Chemother Pharmacol. 2011;68(3):593-601. PubMed PMID: 21116625
  4. Rimando AM, Kalt W, Magee JB, Dewey J, Ballington JR. Resveratrol, pterostilbene, and piceatannol in vaccinium berries. J Agric Food Chem. 2004;52(15):4713-9. PubMed PMID: 15264904
  5. Kambiranda DM, Basha SM, Stringer SJ, Obuya JO, Snowden JJ. Multi-year Quantitative Evaluation of Stilbenoids Levels Among Selected Muscadine Grape Cultivars. Molecules. 2019;24(5):981. PubMed PMID: 30862045
  6. Manickam M, Ramanathan M, Jahromi MA, Chansouria JP, Ray AB. Antihyperglycemic activity of phenolics from Pterocarpus marsupium. J Nat Prod. 1997;60(6):609-10. PubMed PMID: 9214733
  7. Hougee S, Faber J, Sanders A, de Jong RB, van den Berg WB, Garssen J, Hoijer MA, Smit HF. Selective COX-2 inhibition by a Pterocarpus marsupium extract characterized by pterostilbene, and its activity in healthy human volunteers. Planta Med. 2005;71(5):387-92. PubMed PMID: 15931573
  8. Otsuka K, Kuriki D, Kamachi K, Tanaka A, Matsuoka R. Analysis of the Effects of Short-Term Pterostilbene Intake on Healthy Participants: A Pilot Study. J Nutr Sci Vitaminol (Tokyo). 2025;71(1):70-80. PubMed PMID: 40024751
  9. Dellinger RW, Santos SR, Morris M, Evans M, Alminana D, Guarente L, Marcotulli E. Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD(+) levels in humans safely and sustainably: a randomized, double-blind, placebo-controlled study. NPJ Aging Mech Dis. 2017;3:17. PubMed PMID: 29184669
  10. Simic P, Vela Parada XF, Parikh SM, Dellinger R, Guarente LP, Rhee EP. Nicotinamide riboside with pterostilbene (NRPT) increases NAD(+) in patients with acute kidney injury (AKI): a randomized, double-blind, placebo-controlled, stepwise safety study of escalating doses of NRPT in patients with AKI. BMC Nephrol. 2020;21(1):342. PubMed PMID: 32791973
  11. Jensen JB, Dollerup OL, Møller AB, Billeskov TB, Dalbram E, Chubanava S, Damgaard MV, Dellinger RW, Trošt K, Moritz T, Ringgaard S, Møller N, Treebak JT, Farup J, Jessen N. A randomized placebo-controlled trial of nicotinamide riboside and pterostilbene supplementation in experimental muscle injury in elderly individuals. JCI Insight. 2022;7(19):e158314. PubMed PMID: 35998039
  12. Dellinger RW, Holmes HE, Hu-Seliger T, Butt RW, Harrison SA, Mozaffarian D, Chen O, Guarente L. Nicotinamide riboside and pterostilbene reduces markers of hepatic inflammation in NAFLD: A double-blind, placebo-controlled clinical trial. Hepatology. 2023;78(3):863-877. PubMed PMID: 36082508
  13. Holmes HE, Srivastava K, Scalici JM, Dhuguru J, Shea AE, Migaud ME, Dellinger RW. Nicotinamide riboside and pterostilbene reduces frequency and severity of undesirable symptoms of the menopause transition: an open-label, pilot clinical trial. Front Aging. 2026;7:1773667. PubMed PMID: 42211736
  14. Joseph JA, Fisher DR, Cheng V, Rimando AM, Shukitt-Hale B. Cellular and behavioral effects of stilbene resveratrol analogues: implications for reducing the deleterious effects of aging. J Agric Food Chem. 2008;56(22):10544-51. PubMed PMID: 18954071
  15. Chang J, Rimando A, Pallas M, Camins A, Porquet D, Reeves J, Shukitt-Hale B, Smith MA, Joseph JA, Casadesus G. Low-dose pterostilbene, but not resveratrol, is a potent neuromodulator in aging and Alzheimer's disease. Neurobiol Aging. 2012;33(9):2062-71. PubMed PMID: 21982274
  16. Suh N, Paul S, Hao X, Simi B, Xiao H, Rimando AM, Reddy BS. Pterostilbene, an active constituent of blueberries, suppresses aberrant crypt foci formation in the azoxymethane-induced colon carcinogenesis model in rats. Clin Cancer Res. 2007;13(1):350-5. PubMed PMID: 17200374
  17. Hemani R, Patel I, Inamdar N, Campanelli G, Donovan V, Kumar A, Levenson AS. Dietary Pterostilbene for MTA1-Targeted Interception in High-Risk Premalignant Prostate Cancer. Cancer Prev Res (Phila). 2022;15(2):87-100. PubMed PMID: 34675064
  18. Carey AN, Fisher DR, Rimando AM, Gomes SM, Bielinski DF, Shukitt-Hale B. Stilbenes and anthocyanins reduce stress signaling in BV-2 mouse microglia. J Agric Food Chem. 2013;61(25):5979-86. PubMed PMID: 23731018

PubMed Topic Searches

  1. PubMed: pterostilbene randomized controlled trials
  2. PubMed: pterostilbene bioavailability and pharmacokinetics
  3. PubMed: nicotinamide riboside with pterostilbene
  4. PubMed: pterostilbene in Vaccinium berries

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Connections

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