Common misconceptions about sirtuins
Sirtuins are NAD+-dependent histone deacetylases studied as molecular targets in aging, metabolism and stem cell biology. This page separates what the research literature reports from what it does not.
Sirtuins are a family of NAD+-dependent histone deacetylases, abbreviated SIRT, and the family is best known in the research literature for SIRT1 and SIRT3. They are studied as molecular targets in skin biology, metabolic disease, neurodegeneration and stem cell biology, and they are frequently described in the same breath as telomerase, matrix metalloproteinases, antioxidant enzymes, tyrosinase and the melanocortin receptors in reviews of molecular targets in modern cosmetic science [1]. The evidence block used for this page does not supply a sequence, a molecular formula or a molecular weight for any sirtuin, so none is stated here.
The work on sirtuins centres on the NAD+ salvage and nutrient-sensing pathway, in which nicotinamide adenine dinucleotide availability and sirtuin activity are coupled to mitochondrial biogenesis, energy expenditure, oxidative metabolism and insulin sensitivity [2].
Research Studies
Nicotinamide riboside and pterostilbene in amyotrophic lateral sclerosis
Two registered trials have studied a combination of nicotinamide riboside (NR), an NAD+ precursor, and pterostilbene, a polyphenol described as a sirtuin stimulator, in people with amyotrophic lateral sclerosis. The rationale given by the investigators was that increased sirtuin activity together with increased NAD availability may delay disease progression, and the stated aim was to test whether the combination could inhibit neurodegeneration in ALS [4][5]. These are trial records describing planned or ongoing work in a clinical population; they are not reports of an established effect.
Nicotinamide riboside and pterostilbene in muscle regeneration in elderly humans
A separate registered study examined the same combination in elderly human participants, with skeletal muscle regeneration as the focus. The background given is that muscle satellite cells lose quiescence with age and that animal studies have identified sirtuin activation as a common denominator for increasing satellite cell function and activity [6]. The human work is framed as a test of whether the animal findings carry over, which is the correct framing: the satellite cell evidence cited in that record is animal-only.
Sirtuin activators and weight loss
A registered trial record on sirtuin activators and weight loss describes obesity as a chronic, multifactorial disease and notes that long-term effectiveness of lifestyle-based weight management remains limited. It identifies the SIRT family, particularly SIRT1 and SIRT3, as a target of interest because of involvement in mitochondrial biogenesis, energy expenditure, oxidative metabolism and insulin sensitivity, and it names bioactive sirtuin-activating compounds including nicotinamide riboside [2]. The record describes a research question in a clinical population; it does not report an outcome.
Sirtuins and molecular targets in cosmetic science
A review of molecular targets in modern cosmetic science places histone deacetylases, particularly sirtuins, alongside telomerase, matrix metalloproteinases, antioxidant enzymes, CD44, tyrosinase, MITF and melanocortin receptors as targets that regulate DNA repair, gene expression and related processes in skin [1]. This is a review of targets, not a set of trial results, and the skin-aging material it covers is largely mechanistic.
Nutrient-sensing pathways in adult stem cells
A review of nutrient-sensing pathways in adult stem cells reports that mTOR, AMPK, sirtuins and insulin/IGF-1 signalling act as central regulators of adult stem cell fate by modulating cellular metabolism, and proposes a framework integrating these pathways into a network governing metabolic transitions [7]. The finding is a framework for stem cell fate control, not a demonstration of an intervention effect.
NAD+ in cardiovascular disease
A review of nicotinamide adenine dinucleotide in cardiovascular disease reports that NAD+ is an important redox cofactor in energy metabolism and surveys current understanding of its role in cardiovascular disease, including activation of the rate-limiting enzyme in NAD+ biosynthesis [8]. The material is a review of mechanism in a disease context.
Sirtuins in ovarian aging
A review of mechanistic insights into aging and longevity reports that ovarian aging involves progressive follicular reserve depletion, mitochondrial dysfunction, oxidative stress and endocrine decline, and evaluates emerging strategies to preserve reproductive longevity, with sirtuins among the mechanistic contributors examined [9]. This is a review of mechanisms in reproductive aging.
Mitochondrial-derived peptides and vascular aging
A review of mitochondrial-derived peptides reports that humanin, MOTS-c and small humanin-like peptides, encoded by mitochondrial DNA, regulate apoptosis, inflammation and oxidative stress and influence endothelial and vascular smooth muscle cell function in vascular aging [3]. Sirtuins are not the subject of that review, but the mitochondrial and oxidative-stress biology it covers overlaps with the pathway context in which sirtuin research is conducted.
| Compound combination | Model or population | Reported focus |
|---|---|---|
| Nicotinamide riboside + pterostilbene | Amyotrophic lateral sclerosis, clinical trial records | Disease progression, neurodegeneration [4][5] |
| Nicotinamide riboside + pterostilbene | Elderly humans, clinical trial record | Muscle satellite cell function and regeneration [6] |
| Sirtuin-activating bioactive compounds | Obesity, clinical trial record | Mitochondrial biogenesis, energy expenditure, insulin sensitivity [2] |
If you are reading this for personal health reasons
The compounds discussed on this page are supplied for laboratory research use only, and we do not provide dosing information or medical guidance. Anyone considering a compound for themselves should speak to a licensed clinician. Nothing here should be read as a recommendation for personal use.
Sources
- [1] Molecular Targets in Modern Cosmetic Science — https://europepmc.org/article/PMC/PMC13567315
- [2] Sirtuin Activators and Weight Loss — https://clinicaltrials.gov/study/NCT07802548
- [3] Mitochondrial-Derived Peptides as Therapeutics and Biomarkers for Combating Vascular Aging and Associated Cardiovascular Diseases — https://europepmc.org/article/PMC/PMC12951053
- [4] A Trial of Nicotinamide/Pterostilbene Supplement in ALS: The NO-ALS Extension Study — https://clinicaltrials.gov/study/NCT05095571
- [5] The NO-ALS Study: A Trial of Nicotinamide/Pterostilbene Supplement in ALS — https://clinicaltrials.gov/study/NCT04562831
- [6] Effect of Nicotinamide Riboside and Pterostilbene Supplementation on Muscle Regeneration in Elderly Humans — https://clinicaltrials.gov/study/NCT03754842
- [7] Nutrient-sensing pathways in adult stem cells: Orchestrating homeostasis, aging, and disease — https://pubmed.ncbi.nlm.nih.gov/42546460/
- [8] Role of nicotinamide adenine dinucleotide in cardiovascular disease — https://pubmed.ncbi.nlm.nih.gov/42047243/
- [9] Mechanistic insights into aging and longevity: Implications for ovarian function and health — https://pubmed.ncbi.nlm.nih.gov/41833148/