The sources, with their limits still attached
A source link lets you check the claim, including the awkward parts. This list gathers the papers and FDA information used in the guide. Cells, mice and people appear here, but they don’t all answer the same question. The setting stays beside the finding.
Read what was tested
These are the sources cited across the guide. Each note says what a source helped explain and what remains unanswered. A study title can sound broader than the experiment, so I look for what was actually tested before deciding what the result means.
Three details help: the substance, who or what was studied, and what changed. If a claim has swapped any of those, it may be asking the source to carry more than it found. That’s a useful thing to notice.
NAD+ and its precursors
Human NAD+ precursor evidence · Vinten KT et al., 2025.
A review of human trials using NAD+ precursors, ingredients the body can turn into NAD+. It finds limited overall benefit despite some encouraging results.
NAD+ metabolism during ageing · Covarrubias AJ et al., 2021.
Explains NAD+ biology and its roles in ageing cells. Understanding why a molecule matters doesn’t prove that adding more improves health.
NMN and muscle insulin sensitivity · Yoshino M et al., 2021.
Over 10 weeks, NMN improved muscle response to insulin in postmenopausal women with prediabetes. Body composition and HbA1c, a measure of average blood sugar, didn’t change.
NMN in middle-aged adults · Yi L et al., 2023.
This 60-day NMN trial in healthy middle-aged adults reported better walking distance and quality-of-life scores than placebo. It doesn’t settle whether the benefits last.
NR metabolism and trial tolerability · Conze D et al., 2019.
Over eight weeks in healthy overweight adults, NR raised blood NAD+, with no significant difference in side effects. That doesn’t answer every question about longer use.
MOTS-c in cells, mice and human observations
MOTS-c stress and metabolism review · Wan W et al., 2023.
Explains MOTS-c’s origins in mitochondrial DNA, inside the cell’s energy-making structures. A biology review isn’t a human treatment trial.
MOTS-c and nuclear gene activity · Kim KH et al., 2018.
MOTS-c moved into the nucleus, the cell’s control centre, during stress in cell experiments. The result concerns cells, not a demonstrated benefit in people.
MOTS-c exercise and muscle research · Reynolds JC et al., 2021.
Exercise raised people’s own MOTS-c. Giving MOTS-c improved performance in mice; those findings answer different questions.
MOTS-c in a kidney-dialysis group · Bolignano D et al., 2024.
Higher MOTS-c readings were linked to greater risk of death or heart and blood-vessel problems in people receiving kidney dialysis. This measured their own peptide, not a treatment.
Epitalon and the older extract
Epitalon research overview · Araj SK et al., 2025.
An overview of epitalon’s history and proposed effects. Epitalon and Epithalamin, the related gland extract, still need to be kept separate.
Epitalon and telomerase in cultured cells · Khavinson VK et al., 2003.
Epitalon affected telomerase and telomeres, the protective chromosome ends, in cultured human cells. It wasn’t a study of human lifespan.
The Epithalamin longevity report · Khavinson VKh et al., 2003.
The older longevity report used Epithalamin, not synthetic epitalon. Its methods also leave uncertainty about the reported differences in deaths.
Peptide regulation of melatonin in rat cells · Khavinson VKh et al., 2012.
Melatonin rose in rat pineal-cell cultures. That doesn’t demonstrate better sleep in people.
FDA safety information
FDA compounding safety concerns · FDA, 2026.
On the FDA page current as of April 22, 2026, withdrawn nominations still carry safety concerns. Withdrawal isn’t clearance for compounding or approval.
FDA’s epitalon safety and evidence review · FDA, 2026.
FDA’s July 2026 briefing raised a theoretical cancer concern from telomerase activation and telomere lengthening. That isn’t an observed cancer outcome in people; long-term animal cancer studies were missing.
A new paper needs an older neighbour
The newest paper doesn’t automatically have the final word. Older work can show what changed, what was already known and which questions remain open. I find that more useful than treating publication order as a contest. There’s no trophy for being the last PDF opened.
Much of the older epitalon work came from one research group in St. Petersburg. That’s another reason to ask who repeated a result. A newer publication date alone doesn’t tell us whether a different group found the same thing.
Much of the older epitalon work came from one research group in St. Petersburg. A newer date alone doesn’t establish replication.