Researchers can now compare a promising brain-protein pathway with the limited human evidence available, giving shoppers a clearer reason to treat the mouse findings as research rather than a proven anti-aging solution. Restoring Menin improved several age-related changes in mice, while the amino acid D-serine improved cognition without reproducing the broader physical effects.
The result suggests a possible new target for healthy-aging research, but does not show that a supplement can slow or reverse aging in people.
What did restoring Menin change in mice?
A study led by Lige Leng of Xiamen University and colleagues, published on March 16, 2023, in the open-access journal PLOS Biology, examined a pathway involving Menin, a protein found in the hypothalamus. The hypothalamus helps coordinate metabolism and other essential functions.
Menin levels declined with age in certain neurons in the ventromedial hypothalamus, an area involved in regulating metabolism. Researchers did not find the same decline in astrocytes or microglia, two types of cells that support and protect the brain. This suggested that the age-related change affected particular cells rather than the entire region.
To test whether reduced Menin could contribute to aging, the researchers created mice in which Menin could be selectively removed. Lowering Menin in younger mice increased inflammation in the hypothalamus and produced several aging-related traits:
- Lower bone mass
- Thinner skin
- Cognitive decline
- A modestly shorter lifespan
The study also identified changes in D-serine, an amino acid involved in activating receptors that help neurons adjust their connections during learning and memory. Mice with less Menin had lower D-serine levels because an enzyme involved in producing the amino acid became less active.
Did Menin restoration improve aging-related signs?
The researchers delivered the Menin gene into the hypothalamus of 20-month-old mice, allowing cells in that brain region to produce more of the protein. After 30 days, the treated mice had thicker skin, greater bone mass, and better results on tests of learning, cognition, and balance.
D-serine levels also rose in the hippocampus, a brain region important for learning and memory. The researchers reported that restoring Menin extended the treated mice’s lifespan.
A separate experiment supplied D-serine in drinking water for three weeks. That treatment improved cognitive performance, including in older mice, but it did not reproduce Menin restoration’s broader improvements in physical aging traits.
Why do D-serine supplements require caution?
The experimental treatment used D-serine. Foods containing serine, including soybeans, eggs, fish, and nuts, provide L-serine as part of dietary protein. The body can convert L-serine into D-serine, but the two forms are not interchangeable. Eating those foods is therefore not equivalent to receiving the D-serine used in the mouse experiment.
Later research also shows that more D-serine does not necessarily produce better outcomes in every biological setting. A 2025 study in Cellular and Molecular Life Sciences used mice engineered to develop features of Alzheimer’s disease. An early rise in D-serine accompanied disrupted brain signaling, while genetic removal of the enzyme that produces D-serine prevented or reduced several later cognitive problems.
A September 16, 2026, study in the Journal of Alzheimer’s Disease found that an L-serine-enriched diet increased blood levels of both forms of serine and partially restored a measure of new neuron production in a different Alzheimer’s mouse model. It did not improve amyloid buildup. That experiment did not test D-serine supplementation as a human anti-aging treatment.
What does the evidence mean for people?
The human evidence remains limited. A small randomized study published in 2016 tested a single dose of D-serine in 50 healthy older adults. Participants improved on one measure of a computerized maze task, but the study found no significant benefit on the remaining cognitive tests or on mood measures.
That trial did not establish lasting memory benefits, slower aging, or the safety of prolonged D-serine use in older adults. Researchers also still need to determine what causes Menin to decline, how much age-related decline it contributes to, how long any benefits may last, and whether changing Menin or D-serine levels could cause unintended effects.
What to do now
- Do not treat the mouse findings as proof that D-serine reverses aging in people.
- Read labels for the specific form of serine, because L-serine in food and experimental D-serine treatment are not interchangeable.
- Consider the human evidence when assessing a supplement. The small older-adult study found a benefit on only one cognitive measure and did not establish lasting memory effects.
- Watch for research that tests the Menin pathway in people rather than only in cells or mice.
FAQ
Does restoring Menin reverse aging?
Restoring Menin improved several aging-related signs and extended lifespan in treated mice. The study did not show that the treatment reverses human aging.
Can D-serine supplements reverse aging?
D-serine improved cognitive performance in mice but did not reproduce the broader physical improvements seen after Menin restoration. Human evidence does not establish it as an anti-aging treatment.
Are foods that contain serine the same as D-serine supplements?
No. Foods such as soybeans, eggs, fish, and nuts contain L-serine, while the mouse treatment used D-serine. The body can convert L-serine into D-serine, but the forms are not interchangeable.
