The cosmetics industry sells products that work on the surface. NAD⁺ decline changes the skin from within. Here you will find out what is actually happening in the skin cells, why creams are not enough, and what NMN achieves that no external application can reach.
Women spend more on skincare than on almost any other personal category. Serums, retinoids, vitamin C, collagen creams, peptide formulas. The industry generates hundreds of billions of dollars annually with a promise: the right product, applied in the right order, keeps skin the way it used to be. Some of it works. Most of it works on the periphery. None of it touches the reason why the skin began to change in the first place.
The changes that most women notice in their 30s and 40s are not a surface problem. The loss of firmness, the change in texture, the way light hits the face differently, the fine lines in places that seemed unchanged just a few years ago—this is all a cellular problem.
The cells that produce collagen and elastin, keeping the skin firm and plump, are producing less of them. They repair damage more slowly. And they renew themselves less efficiently. The reason is a decline in cellular energy supply that no cream can reach. NAD⁺ is the fuel for this supply, and NMN is what restores it.
What skin aging really is at the cellular level
The skin consists of several layers. The outermost is the epidermis. It is constantly renewing itself: cells divide in the basal layer, slowly migrate upward, maturing in the process, and are eventually shed.
Beneath it lies the dermis. This is where fibroblasts work—the cells that produce collagen, elastin, and hyaluronic acid.
The structural quality of the skin depends entirely on these fibroblasts: their firmness, their elasticity, their thickness, and their ability to retain moisture. What matters is what the fibroblasts produce and how efficiently they repair themselves.
Fibroblast function decreases with age. The most important reason for this is cellular energy. Fibroblasts are very active cells. Producing collagen is metabolically demanding. And keeping the enzymatic machinery for DNA repair intact requires constant energy.
When this energy supply drops—and it does, because NAD⁺ levels decline from the mid-20s onwards—fibroblasts become slower. Collagen production decreases. DNA damage in skin cells accumulates faster than it is repaired. The skin begins to change, visible from the outside, but originating entirely within the cell.
The collagen numbers and what they mean
From the mid-20s, collagen production decreases by about 1% per year. By her mid-40s, a woman has lost about 20% of the collagen she had at 25.
In the first five years after menopause, women lose up to 30% of their remaining skin collagen. The reason is the sharp drop in estrogen: estrogen directly signals fibroblasts to produce collagen. Without it, this signal becomes significantly weaker.
Two decades of gradually declining cellular energy followed by an abrupt hormonal shift—together, this results in the visible acceleration of skin aging that many women notice in their late 40s and early 50s.
These figures are not estimates. They come from research into skin biology and menopause. The annual 1% decline in collagen is documented in several studies. The acceleration after menopause is one of the most frequently replicated findings in dermatological research.
What is discussed less frequently alongside these figures is the cellular energy mechanism behind them. And with it, the question of what it means for the progression of skin aging to address this exact mechanism.
From the mid-20s, collagen production decreases by 1% per year. In the first five years after menopause, women lose up to 30% more.
Where NAD⁺ comes in for skin aging
NAD⁺ is required for the enzymatic processes that make the work of fibroblasts possible in the first place.
It activates PARP enzymes. These recognize and repair DNA damage that accumulates in skin cells—through cell division and through UV radiation, environmental pollution, and oxidative stress. It powers the mitochondria that generate the energy fibroblasts use to build collagen. And it activates sirtuins, which regulate the inflammatory response in skin tissue and control how actively skin cells renew themselves through epigenetic signals.
If enough NAD⁺ is present, skin cells repair themselves efficiently. Fibroblasts produce collagen at a steady pace. Inflammatory processes in the tissue remain regulated. And the renewal cycle that keeps the epidermis fresh and responsive runs on time.
If NAD⁺ levels drop, all these processes slow down simultaneously. The skin does not fail suddenly. It builds up a deficit in several systems in parallel.
This is exactly why skin aging looks the way it does: as a gradual change on many levels at once, which no single topical active ingredient can fully address.
Why topical collagen does not work—and how NMN works differently
Collagen molecules are too large to pass through the skin barrier in significant amounts. Most collagen creams therefore act on the surface. They can temporarily improve the appearance of the skin by forming a film on it. But they do not reach the dermis and do not reach the fibroblasts that actually produce structural collagen.
Ingested collagen has a different problem. During digestion, it is broken down into amino acids and distributed throughout the body wherever these amino acids are needed. The body does not preferentially send them to the face or the dermis. A supplement cannot dictate to the body where to use the delivered material.
NMN works in a fundamentally different way. It does not provide the raw material for collagen. It can restore the cellular conditions under which fibroblasts produce collagen themselves—at the speed and quality they were capable of before the energy supply declined.
That is the crucial difference. NMN does not give the skin something from the outside that it needs. It can give the skin back its own ability to do what it has always been able to do.
What is realistic to expect—and when
Skin changes are not the first thing women notice with NMN. Sleep changes in the first one to two weeks. Energy levels stabilize in weeks two to four. The skin follows from the second to third month.
This is consistent with biology. Fibroblasts respond to a better energy supply over weeks. Collagen synthesis is a slow process. And the renewal cycle of the epidermis takes about 28 days in younger women and slows down with age.
Visible improvements in skin quality take longer with any measure that works at the cellular level than improvements in energy or sleep. In return, they are usually more lasting because they reflect a genuine change in cellular function and not a temporary effect.
What women who take NMN for three months or longer describe is not a dramatic transformation overnight. It is skin that looks different without being able to pinpoint exactly why, because nothing was changed externally. The texture improves. The light hits the face differently. The skin feels different.
These are the signs of cells that have enough energy for their repair work. And that is exactly what NMN makes possible through the restoration of NAD⁺.
The skin reflects the condition of the cells beneath it. Most skincare products treat the reflection. NMN treats the cells. This difference is not a marketing statement. It is the difference between the surface of a problem and its root cause.
Sources
- Brincat, M. P., Baron, Y. M., & Galea, R. (2005). Effect of menopause on the skin. Climacteric, 8(Suppl 1), 11–23. https://doi.org/10.1080/13697130500161963
- Shuster, S., Black, M. M., & McVitie, E. (1975). The influence of age and sex on skin thickness, skin collagen and density. British Journal of Dermatology, 93(6), 639–643. https://doi.org/10.1111/j.1365-2133.1975.tb05100.x
- Covarrubias, A. J., Perrone, R., Grozio, A., & Verdin, E. (2021). NAD+ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology, 22(2), 119–141. https://doi.org/10.1038/s41580-020-00313-x
- Yaku, K., Okabe, K., & Nakagawa, T. (2018). NAD metabolism: Implications in aging and longevity. Ageing Research Reviews, 47, 1–17. https://doi.org/10.1016/j.arr.2018.05.006
- Massudi, H., Grant, R., Braidy, N., et al. (2012). Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLOS ONE, 7(7), e42357. https://doi.org/10.1371/journal.pone.0042357
- Yoshino, M., Yoshino, J., Kayser, B. D., et al. (2021). Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science, 372(6547), 1224–1229. https://doi.org/10.1126/science.abe9985