NMN Increases Hair Thickness in Middle-Aged Women, Study Shows
A 12-week clinical trial found that 500mg daily NMN supplementation increased hair diameter by approximately 5% in middle-aged women, whilst also improving subjective measures of hair quality.
Published in the journal Cosmetics, this human study from Mitsubishi Corporation's life sciences division provides the first clinical evidence that NMN may help reverse hair thinning, though the results include some complexity worth understanding.
Key Findings
- Hair diameter increased from 75µm to 79µm after 12 weeks of NMN supplementation
- Hair elongation rate improved - more hairs showed growth three days after shaving
- Hair count decreased slightly - fewer total hairs, though this may be seasonal
- Subjective hair quality improved significantly - participants reported better volume, gloss, elasticity, and less hair loss
The Study Design
Fifteen middle-aged women took 500mg of NMN daily in tablet form for 12 weeks. This dose is half what previous studies used for skin improvements, suggesting relatively modest dosing.
Researchers measured:
- Hair diameter using microscopy
- Hair growth rate after shaving a small scalp area
- Hair count per square centimetre
- Subjective assessments via questionnaire
- Metabolic changes related to NAD+ and energy production
Hair Thickness Results
The primary finding was clear: NMN increased average hair diameter from approximately 75 micrometres to 79 micrometres over 12 weeks. This represents about a 5% increase in thickness.
Thicker hair shafts create the appearance of fuller, healthier hair. Even modest increases in diameter can noticeably improve hair quality and reduce the appearance of thinning.
Two participants were excluded as statistical outliers, suggesting individual response to NMN varies. Some people may see more dramatic improvements whilst others see less.
The Hair Count Paradox
The study revealed an interesting contradiction:
Increased Elongation Three days after shaving a small area, the number of elongated hairs increased from about 56 to 88 per square centimetre. This suggests NMN speeds hair growth rate.
Decreased Total Count However, the total number of actively growing hairs decreased from approximately 191 to 168 per square centimetre.
Likely Explanation The researchers attribute this to seasonal hair loss rather than an NMN effect. Human hair naturally cycles through growth and shedding phases, with seasonal variations common. The study period may have coincided with a natural shedding phase.
Importantly, despite lower hair count, the increase in diameter meant overall hair volume and appearance improved according to participants' assessments.
Subjective Improvements
Participants reported multiple improvements in how their hair looked and felt:
Reduced Concerns:
- Less fatigue (which may indirectly affect hair perception)
- Reduced grey hair perception
- Less concern about hair parting visibility
- Less hair loss upon waking
- Less hair loss when shampooing
Improved Quality:
- Better hair elasticity
- Easier combing
- Increased gloss
- Enhanced volume
These subjective improvements suggest that even modest objective changes in hair diameter translate to noticeable improvements in day-to-day hair quality.
How NMN May Improve Hair
The researchers identified several mechanisms through which NMN might benefit hair:
NAD+ Restoration Hair follicles are metabolically active structures requiring substantial cellular energy. NAD+ levels decline with age, potentially affecting follicle function. NMN boosts NAD+, supporting the energy demands of hair growth.
Mitochondrial Function The study found evidence of improved mitochondrial function and energy metabolism. Better cellular energy production could support the demanding process of hair growth and maintenance.
Metabolic Changes After NMN supplementation, participants showed:
- Increased tryptophan and glutamine (NAD+ synthesis precursors)
- Elevated amino acids related to energy metabolism (leucine, isoleucine)
- Increased creatine and creatinine
- Reduced lactate (suggesting more efficient energy production)
These changes indicate enhanced mitochondrial ATP production and amino acid metabolism - both relevant to hair follicle function.
Reduced Fatigue The researchers noted that reduced fatigue may contribute to improved hair perception. When people feel less tired, they may experience less stress, which itself affects hair health. This psychological component shouldn't be dismissed.
Context: Hair and Ageing
Hair thinning is a common concern as we age, affecting quality of life for many people. Age-related hair changes include:
- Decreased hair diameter (thinner individual strands)
- Reduced hair density (fewer hairs overall)
- Slower growth rate
- Changes in hair texture and quality
- Increased brittleness
These changes result from multiple factors:
- Reduced cellular energy in follicles
- Oxidative stress damage
- Inflammation
- Hormonal changes
- Nutritional deficiencies
NMN appears to address some (but not all) of these factors, primarily through supporting cellular energy metabolism.
Study Limitations
Small Sample Size Fifteen participants is quite small. Larger studies are needed to confirm these findings and better understand individual variation in response.
No Control Group This study lacked a placebo control group, making it impossible to separate NMN effects from placebo effects or natural variation. The subjective improvements particularly need placebo-controlled validation.
Short Duration Twelve weeks is relatively brief. Longer studies would reveal whether benefits continue, plateau, or reverse over time.
Single Dose Only 500mg daily was tested. Different doses might produce different results.
Female Participants Only The study included only middle-aged women. Results may differ in men or other age groups.
Seasonal Confound The decrease in hair count may have been seasonal rather than NMN-related, but this wasn't definitively established.
Practical Considerations
Who Might Benefit
Based on this research, NMN supplementation for hair health seems most relevant for:
- Middle-aged adults (40s-60s) experiencing hair thinning
- Those noticing decreased hair diameter rather than pattern baldness
- People seeking modest improvements rather than dramatic regrowth
- Individuals interested in overall cellular health (hair benefits as a bonus)
Dosage
The study used 500mg daily. This is a standard NMN dose for general health benefits. Our NMN Supplement 500mg provides this research-supported dosage.
Realistic Expectations
NMN won't regrow hair in areas of complete baldness or reverse pattern hair loss (androgenic alopecia). It may help with:
- Age-related thinning
- Reduced hair diameter
- Hair quality and texture
- Supporting healthy hair growth
Results, if they occur, develop over months, not days or weeks.
Not a Hair Loss Treatment
This research examined hair thinning in middle-aged women, not medical hair loss conditions. If you're experiencing significant hair loss, consult a doctor to rule out underlying conditions (thyroid problems, nutritional deficiencies, autoimmune issues).
Combination Approaches
The article mentions that combining NMN with other compounds might provide additional benefits:
Senolytics Research suggests clearing senescent cells from hair follicles may promote hair growth. Combining NAD+ support with senolytic compounds could theoretically offer complementary benefits.
mTOR Inhibitors Some research shows mTOR inhibition promotes hair growth. However, mTOR also plays important roles in muscle maintenance and other functions, making this approach more complex.
Our Approach
Rather than complex combinations with unknown interactions, our NMN Supplement focuses on high-quality NAD+ support. This provides a foundation for cellular health that may support hair quality alongside numerous other benefits.
The Bigger Picture
This study shouldn't be viewed in isolation. It's part of broader evidence that:
Cellular Energy Matters Supporting mitochondrial function and cellular energy has wide-ranging benefits throughout the body, including metabolically active tissues like hair follicles.
NAD+ Decline Affects Multiple Systems Age-related NAD+ depletion affects energy-demanding tissues. Restoring NAD+ may support function across multiple organ systems.
Hair Reflects Overall Health Hair quality often mirrors overall metabolic and cellular health. Improvements in hair may indicate broader improvements in cellular function.
What This Means for You
Evidence of Benefit This study provides preliminary human evidence that NMN may improve hair thickness and quality in middle-aged adults. The effects are modest but measurable.
Safe Approach Unlike pharmaceutical hair loss treatments with potential side effects, NMN has an excellent safety profile and provides broader health benefits beyond hair.
Manageable Expectations Don't expect dramatic hair regrowth. Do consider NMN as part of a comprehensive approach to healthy ageing that may include modest hair quality improvements.
Additional Benefits Even if hair improvements are modest, NMN supplementation supports cellular energy, NAD+ levels, and metabolic function throughout the body. Hair benefits come as part of a broader health package.
Our NMN Supplement
Pharmaceutical-grade NMN providing 500mg per capsule - the same dose used in this hair study. Supports:
- Cellular NAD+ production
- Mitochondrial energy metabolism
- Healthy ageing processes
- Multiple aspects of cellular health
Why Choose Our NMN:
- Manufactured to pharmaceutical standards in GMP-certified UK facilities
- Rigorous purity and quality control
- Research-supported 500mg dosage
- Optimal bioavailability
- No unnecessary additives
The Bottom Line
This small clinical trial provides the first human evidence that NMN supplementation may improve hair thickness and quality in middle-aged women. A 5% increase in hair diameter over 12 weeks, combined with improved subjective assessments of hair quality, suggests NMN supports hair health through its effects on cellular energy metabolism.
However, realistic expectations are important. NMN isn't a hair loss cure or dramatic regrowth treatment. It appears to modestly improve hair diameter and quality as part of broader cellular health support. The decrease in hair count complicates interpretation, though researchers attribute this to seasonal variation rather than NMN effects.
For those already interested in NMN for its broader health benefits - cellular energy, NAD+ restoration, metabolic support - these hair findings add another potential benefit to the list. For those specifically seeking hair improvements, NMN represents a safe, research-backed option worth considering, particularly if you're experiencing age-related thinning rather than pattern baldness.
The study's limitations - small size, lack of placebo control, short duration - mean more research is needed. But as a preliminary investigation, it provides encouraging evidence that supporting cellular energy metabolism with NMN may help maintain hair quality as we age.
Reference: Fukumoto S, et al. (2025). "Oral Supplementation of Nicotinamide Mononucleotide (NMN) Improves Hair Quality and Subjective Perception of Hair Appearance in Middle-Aged Women." Cosmetics, 12(5), 204.
These statements have not been evaluated by the Medicines and Healthcare products Regulatory Agency (MHRA). These products are not intended to diagnose, treat, cure or prevent any disease. This article discusses research findings and is not medical advice. NMN is not a treatment for hair loss conditions. Always consult with a healthcare professional regarding hair loss concerns.