Editor’s Note (September 2026): This article was originally published in August 2020 and reflects research available at that time. It has since been reviewed for accuracy and clarity. Claims concerning growth hormone, IGF-1, and treatments for hair loss have been clarified to better reflect the evidence discussed in the original research.
Key Takeaways
Insulin-like growth factor 1 (IGF-1) participates in the signaling processes involved in hair-follicle growth and development.
Research has linked IGF-1 deficiency and altered IGF-1 signaling with certain forms of hair loss, but this does not mean that low IGF-1 is the cause of most alopecia.
A 2018 paper described several clinical cases involving growth hormone deficiency or previous pituitary surgery that provided additional evidence for a possible relationship between IGF-1 and hair growth.
The evidence did not establish IGF-1 or growth hormone supplementation as a routine treatment for common hair loss.
IGF-1 is involved in signaling pathways that help regulate hair follicle growth and development.
Hair growth depends on a complex interaction among genetics, hormones, signaling molecules, age, health conditions, and environmental factors.
One signaling molecule that has attracted scientific interest is insulin-like growth factor 1 (IGF-1).
Research suggests that IGF-1 participates in hair-follicle proliferation, differentiation, tissue remodeling, and regulation of the hair-growth cycle.
A paper published in Skin Appendage Disorders examined clinical observations that provide further evidence for a relationship between IGF-1 and human hair growth.
What Is IGF-1?
Insulin-like growth factor 1, commonly abbreviated IGF-1, is a hormone and growth factor involved in normal growth and development.
Growth hormone stimulates IGF-1 production, and the growth hormone/IGF-1 system has important effects throughout the body.
Within hair follicles, IGF-1 appears to participate in signaling involving dermal papilla cells and other components responsible for regulating follicular growth and differentiation.
Previous experimental research has suggested that IGF-1 signaling influences the hair-growth cycle and development of the hair shaft.
Researchers have also reported that dermal papilla cells from balding scalp follicles can produce less IGF-1 than cells from non-balding follicles.
These observations suggest an association between IGF-1 signaling and hair biology, but they do not establish low IGF-1 as the sole or primary cause of common hair loss.
Clinical Observations Linking IGF-1 and Hair Growth
In his 2018 paper, dermatologist Ralph M. Trüeb discussed clinical observations involving patients with growth hormone deficiency or a history of pituitary surgery.
One case involved a 10-year-old boy with primary growth hormone deficiency and hypotrichosis, a condition characterized by reduced hair growth.
Despite receiving recombinant growth hormone treatment and showing improvements in growth, the patient’s sparse scalp hair persisted.
The paper also described adults with androgenetic-pattern hair loss who had previously undergone pituitary surgery.
One male patient with a history of surgery for a Rathke cleft cyst showed low IGF-1 levels and did not respond satisfactorily to prolonged treatment with topical minoxidil and oral finasteride.
A female patient who had undergone surgery for a pituitary tumor similarly experienced androgenetic-pattern hair loss that showed little response to topical minoxidil.
These observations led the author to suggest that impaired growth hormone/IGF-1 signaling could potentially contribute to hair-growth abnormalities in some patients.
What Do These Cases Actually Show?
The cases provide clinical evidence supporting a biological relationship between IGF-1 and hair growth, but they have important limitations.
Case reports cannot demonstrate that low IGF-1 directly caused an individual’s hair loss. They also cannot establish that increasing IGF-1 would restore hair growth.
Hair loss has many potential causes, including genetic predisposition, autoimmune disease, hormonal changes, medications, nutritional deficiencies, illness, and age.
The patients described in the paper also had unusual endocrine and medical histories, meaning their experiences should not automatically be applied to people with common male- or female-pattern hair loss.
Hormones and Hair Growth
IGF-1 is only one part of a complicated network controlling the hair follicle.
Androgens are particularly important in androgenetic alopecia, and research indicates that they can influence IGF-1 activity within dermal papilla cells.
Other hormonal and biological factors can also affect hair growth.
Understanding these signaling pathways could eventually help researchers identify new approaches to treating certain types of alopecia. However, identifying a biological pathway involved in hair growth is different from demonstrating that manipulating that pathway is a safe and effective treatment.
Does Growth Hormone Treat Hair Loss?
The evidence discussed in this paper does not establish recombinant growth hormone as a treatment for ordinary hair loss.
In fact, the child described in the paper continued to have sparse hair despite growth hormone treatment, even though his physical growth improved.
Growth hormone is a prescription treatment used for specific medically diagnosed conditions. It should not be used for cosmetic hair restoration without an appropriate medical indication.
Similarly, the relationship between IGF-1 and hair-follicle biology does not mean that taking substances intended to raise IGF-1 will prevent or reverse alopecia.
What About Platelet-Rich Plasma?
Platelet-rich plasma (PRP) has separately been investigated as a treatment for some forms of non-scarring hair loss, including androgenetic alopecia.
PRP contains numerous signaling proteins and growth factors, and its possible effects on hair follicles involve multiple biological pathways.
However, it would be misleading to describe PRP simply as a treatment for IGF-1 deficiency. Its potential role in hair restoration is a separate clinical question.
Final Thoughts
Research supports an important biological role for IGF-1 in hair-follicle growth, differentiation, and regulation.
Clinical observations involving growth hormone deficiency and patients who underwent pituitary surgery provide additional evidence that disruption of the growth hormone/IGF-1 pathway may influence hair growth in certain circumstances.
However, the available evidence does not show that low IGF-1 causes most hair loss or that raising IGF-1 will reverse alopecia.
The findings are better understood as evidence about the biology of hair growth and a potential area for further research rather than justification for using growth hormone or IGF-1 as routine hair-loss treatments.
Reference
Trüeb, R. M. (2018). Further clinical evidence for the effect of IGF-1 on hair growth and alopecia. Skin Appendage Disorders, 4(2), 90–95. https://doi.org/10.1159/000479333