ThornevsTru Niagen

Thorne's longevity line centers on raising NAD+ (nicotinamide adenine dinucleotide), a coenzyme essential for mitochondrial energy production and DNA repair that declines with age. ResveraCel delivers nicotinamide riboside (NR), a vitamin B3 form the body converts into NAD+, which in turn fuels "sirtuin" enzymes linked to cellular maintenance. The formula adds trans-resveratrol and quercetin phytosome (intended to support sirtuin activity and absorption) plus betaine to support methylation, since NAD+ metabolism consumes methyl groups. In plain terms: NR is the raw material that tops up your NAD+ tank; the other ingredients are meant to help that tank get used efficiently. This is a plausible mechanism, but a mechanism is not the same as a proven health outcome.

Tru Niagen delivers Niagen, a patented form of nicotinamide riboside (NR), a relative of vitamin B3. Your cells convert NR into NAD+ (nicotinamide adenine dinucleotide), a coenzyme essential for turning food into cellular energy, supporting DNA repair, and fueling the activity of enzymes called sirtuins. NAD+ levels tend to decline with age, and the theory is that replenishing NAD+ may support healthier cellular aging. Importantly, the supplement reliably raises blood NAD+; whether that higher NAD+ produces meaningful health benefits in people is still an open question.

The strongest evidence is narrow but consistent: NR reliably raises NAD+. A randomized, double-blind, placebo-controlled trial of 120 adults aged 60-80 testing an NR-plus-pterostilbene formula found whole-blood NAD+ rose roughly 40% at the recommended dose and about 90% at double dose by week 4, sustained over the 8-week trial (Dellinger et al., npj Aging, 2017). A 2025 eClinicalMedicine long-COVID trial using 2000 mg/day NR raised NAD+ about 2.6-3.1 fold, yet showed no statistically significant improvement in its primary cognition outcome or in fatigue, sleep, or mood versus placebo; exploratory analyses hinted at some symptom improvement in those who took NR for at least 10 weeks, but this was not a confirmed result. Resveratrol's longevity benefits remain unproven in humans: comprehensive reviews cite poor bioavailability and no conclusive clinical evidence for anti-aging outcomes. So: NAD+ goes up; downstream "live longer/feel younger" benefits are not yet demonstrated.

The strongest, most consistent finding is at the biomarker level: in a randomized, double-blind, placebo-controlled trial of 140 overweight but otherwise healthy adults (Conze et al., 2019), Niagen raised whole-blood NAD+ dose-dependently within two weeks (about 22% at 100mg, 51% at 300mg, and 142% at 1000mg per day), and the increase was sustained over the 8-week study. Downstream clinical benefits are far less convincing. Dollerup et al. found that NR (1000mg twice daily, 2000mg/day for 12 weeks) raised NAD+ but did not meaningfully improve insulin sensitivity, skeletal-muscle mitochondrial function, or body composition in obese, insulin-resistant men. A 2018 crossover trial in middle-aged and older adults (Martens et al., 1000mg/day) raised NAD+ by roughly 60% but found that reductions in blood pressure and aortic stiffness did not reach statistical significance. So NR clearly elevates NAD+; the evidence that it slows aging or improves performance in healthy people remains weak.

In clinical trials, NR-based formulas were well tolerated with no serious adverse events; mild, uncommon effects included gastrointestinal upset (nausea, bloating), more frequent at higher doses. Resveratrol at high doses can cause GI symptoms and, because it may mildly inhibit platelet aggregation and certain drug-metabolizing enzymes, can theoretically increase bleeding or interact with medications. Quercetin is generally well tolerated. There are no documented serious safety signals at label doses, but long-term, high-dose safety data are limited, so periodic check-ins with a clinician are sensible. This is general information, not medical advice.

Across trials at doses up to 1000-2000mg/day, Niagen has been well tolerated, with adverse-event rates similar to placebo and, notably, no skin flushing (a common complaint with older high-dose niacin). In real-world use, mild and transient effects can include nausea, stomach discomfort, bloating, headache, or fatigue. No serious adverse events have been clearly attributed to NR in published trials. Long-term safety beyond a few months is less studied, and because NAD+ influences cell metabolism, people with cancer or other proliferative conditions should be cautious and consult a physician before use.

As of 2026, ResveraCel runs about $58-60 for a one-month supply (60 capsules at the standard 2-capsules-once-daily serving), with roughly 10% off via Thorne's subscription. Third-party retailers (Amazon, iHerb, Vitacost, and the Mayo Clinic Store) price it similarly, occasionally a few dollars less. Supplements are not covered by insurance, but US buyers can typically pay with HSA/FSA funds. Thorne's separate Biological Age test is about $95, and note that the required blood panel is an added, separate cost you arrange yourself.

As of 2026, Tru Niagen 300mg costs $49 for a 30-count bottle (about one month) at full price directly from the manufacturer, or $39.20/month on subscription (20% off, with free shipping). Larger bottles lower the per-capsule cost: a 90-count is $127 ($101.60 on subscription) and a 180-count is $244 ($195.20 on subscription), which works out to roughly $1.08-$1.41 per day depending on size and whether you subscribe. At higher daily doses, monthly cost rises proportionally. As a dietary supplement it is not covered by insurance and rarely qualifies for HSA/FSA reimbursement without a doctor's letter. Third-party retailers (Amazon, Costco, Walmart) sometimes price below MSRP.

Best for generally healthy adults, often 40+, who want a high-purity NAD+ precursor and value third-party certification (athletes benefit from NSF Certified for Sport options). Avoid or get medical clearance if you are pregnant or breastfeeding, have liver or kidney disease, or take blood thinners or blood-pressure medication, since resveratrol can affect clotting and drug metabolism. People on chemotherapy or with hormone-sensitive conditions should consult an oncologist before using resveratrol-containing products. It is a supplement, not a treatment for any diagnosed disease.

Tru Niagen is aimed at generally healthy adults interested in cellular-aging support and NAD+ optimization. It is not recommended during pregnancy or breastfeeding (it has not been tested in these groups), and people with cancer or a cancer history should consult a physician first, since NAD+'s role in cell proliferation is not fully understood. Anyone on prescription medications, with kidney or liver disease, or undergoing chemotherapy should also talk to a clinician before starting. It is a dietary supplement, not a treatment for any disease, and is not intended for children.