What the Research Suggests
When a semen analysis shows a low sperm count, the conversation can move quickly toward IVF or ICSI.
Those options can be valuable. But another question deserves attention: could treating the male partner improve sperm production?
(The obvious answer is yes - but when it comes to fertility assessments too many men are getting the bare minimum of investigations) and left with the incredibly frustrating label of ‘unexplained’. As many in the restorative field will agree - it’s more often than not - ‘under investigated.’
Dr. Alberto Ferlin and colleagues have helped investigate one possibility: FSH therapy, including for selected men whose blood FSH levels are normal. What makes their work distinctive is not the idea that every man needs more hormonal stimulation. It is the effort to understand who might benefit, who probably will not, and why.
What does FSH do in men?
FSH stands for follicle-stimulating hormone. Despite its name, it plays an important role in male fertility.
In the testes, FSH acts on Sertoli cells - the supporting cells that help developing sperm grow and mature. Nearby, Leydig cells produce testosterone, primarily in response to another hormone called LH. Together, these cells help maintain the environment needed for sperm production.
FSH treatment aims to stimulate the Sertoli-cell support system. It is not the same as testosterone treatment.
Why give FSH when the blood level is normal?
FSH is used to help men whose brains are not providing enough hormonal stimulation to the testes. In this situation, gonadotropin treatment - usually hCG, with FSH added when needed - can stimulate sperm production.
Ferlin’s research also asks a different question:
Could additional FSH help some men who are not hormone-deficient, but whose testes are producing too few sperm?
A blood result within the reference range does not necessarily tell us how effectively the whole sperm-producing system is functioning. But it also does not mean that more FSH will help. This is where careful patient selection becomes important.
What makes Ferlin’s research innovative?
A low sperm count describes the result - not necessarily the problem causing it. Lifestyle factors can improve men’s reproductive health as can a restorative reproductive approach. It’s important to find out WHY your partner is having this issue. In the same way a woman’s cycles are considered an important 5th vital sign - so is your partner’s semen analysis. It makes sense that we find out if there are other root cause contributors that need to be addressed for your partner’s overall health and longevity.
Some men may have reduced production of sperm-producing cells. Others may have cells that begin developing but struggle to complete the process. Those situations may respond differently to additional stimulation.
Ferlin and colleagues have investigated these differences rather than treating every low sperm count as the same condition.
In a 1998 placebo-controlled study co-authored by Ferlin, 90 men had low sperm counts and normal FSH. Sixty received FSH and 30 received placebo. Twenty treated men at least doubled their sperm count; none in the placebo group did.
The important finding was not simply that some sperm counts improved. It was that the underlying pattern of sperm development appeared relevant to the response.
Moving toward more personalized male fertility care
Ferlin and colleagues’ 2024 review examines possible ways to improve patient selection, including hormone levels, patterns of sperm-cell development, genetic variations affecting FSH action, and emerging molecular markers.
These are research directions - not a universally validated test panel that can tell every man whether FSH will work.
The goal is more targeted treatment: offering additional stimulation where it may help while avoiding unnecessary injections, expense, and lost time where it is unlikely to make a difference.
Broader research suggests that FSH can improve sperm concentration and pregnancy rates in some men with unexplained infertility. However, study quality and treatment responses vary, and evidence for improved live-birth outcomes remains less certain.
Where does Red Light Therapy fit?
Photobiomodulation, or red light therapy, explores a different possibility: supporting the cells and environment in which sperm develop (just like we support the environment the ovaries are growing in).
Rather than providing the direct hormonal signal supplied by FSH, red light therapy is being investigated for effects on oxidative stress, cellular function, and tissue recovery.
In animal studies of heat-induced testicular injury, PBM has been associated with:
Higher Sertoli- and Leydig-cell counts.
Improved sperm parameters.
Reduced oxidative stress.
Changes in genes involved in maintaining the blood - testis barrier, which helps protect developing sperm.
Improved testosterone levels in some experiments.
Read more about red light therapy for male fertility here
https://blog.tracydonegan.org/blog/red-light-therapy-male-fertility
What should he ask his specialist?
Before considering FSH, a reproductive urologist or andrologist should investigate why sperm production is low. Assessment may include medical history, examination, repeat semen testing, hormone measurements, and further investigations where indicated.
Useful questions include:
“Is there an identifiable cause we can treat?”
“Do my results suggest that additional FSH could help?”
“What evidence supports treatment in someone with my findings?”
“How will we decide whether I am responding?”
“How does this fit with my partner’s fertility timeline?”
FSH treatment usually involves injections over several months, with reassessment commonly beginning around three months. That time commitment should fit into the couple’s wider plan - not automatically delay other appropriate treatment.
Asking Better Questions
Ferlin’s work is not a story about a miracle injection. It is a story about asking a better question.
Not simply, “Can FSH increase sperm production?”
But, “Which men have a problem that additional FSH might actually help?”
That shift - from treating a test result to understanding the biology behind it - is what makes this research valuable. It points toward more individualized male fertility care while acknowledging that many men will not respond.
Educational information only. FSH requires specialist prescribing and monitoring.
References
Foresta C, Bettella A, Ferlin A, et al. Evidence for a stimulatory role of follicle-stimulating hormone on the spermatogonial population in adult males. Fertility and Sterility. 1998;69(4):636–642. doi:10.1016/S0015-0282(98)00008-9.
Foresta C, Bettella A, Garolla A, Ambrosini G, Ferlin A. Treatment of male idiopathic infertility with recombinant human follicle-stimulating hormone: a prospective, controlled, randomized clinical study. Fertility and Sterility. 2005;84(3):654–661. doi:10.1016/j.fertnstert.2005.03.055.
Grande G, Graziani A, Scafa R, Garolla A, Santi D, Ferlin A. FSH therapy in male factor infertility: evidence and factors which might predict the response. Life. 2024;14(8):969. doi:10.3390/life14080969.
Santi D, Granata ARM, Simoni M. FSH treatment of male idiopathic infertility improves pregnancy rate: a meta-analysis. Endocrine Connections. 2015;4(3):R46–R58. doi:10.1530/EC-15-0050.
Photobiomodulation improves histological parameters of testis and sperm quality following testicular hyperthermia in mice. Journal of Lasers in Medical Sciences. 2024. PMCID: PMC11499963.
The impact of photobiomodulation therapy on enhancing spermatogenesis and blood–testis barrier-related gene expression in a mouse model of testicular hyperthermia. Journal of Lasers in Medical Sciences. 2024. PMCID: PMC11459248.
