Loss of libido: when and why it happens, in men and women

Talking about low libido still makes many clinical visits uncomfortable — but it's an extremely common complaint, affecting a significant share of the adult population, across every age group. Understanding when it's most frequent and why it happens is the first step toward treating the topic with the medical seriousness it deserves, instead of silence or guilt.

What the data shows: when sexual desire drops most

The largest population survey ever conducted on this topic, Natsal-3 (the third National Survey of Sexual Attitudes and Lifestyles, in Britain, with more than 15,000 participants), found a consistent pattern: low sexual interest is reported about twice as often in women as in men, across nearly every age group — and, for both sexes, it tends to rise from youth into midlife, peaking between ages 45 and 64.31

Why libido declines in men

• Declining testosterone. This is the most studied hormonal cause — reduced sexual desire symptoms, combined with consistently low testosterone levels, characterize hypogonadism, which becomes more common from midlife onward.15
• Chronic disease and metabolic factors. Diabetes, hypertension, obesity, and cardiovascular disease all have a direct impact on sexual function, through both vascular and hormonal mechanisms.
• Medications. Antidepressants (especially SSRIs) are among the most common medication-related causes of low libido, with sexual side effects reported in a significant proportion of users — on top of depression itself, which already reduces sexual desire even without treatment.33
• Psychological and relationship factors. Stress, anxiety, poor sleep, and relationship conflict also play a meaningful role — often combined with physical causes, not separate from them.

Why libido declines in women

• Menopause and hormonal decline. The menopausal transition is associated with a marked rise in the prevalence of low sexual desire, mainly linked to declining estradiol — the PRESIDE population study, one of the largest ever conducted on the topic, documented this pattern in tens of thousands of American women.32 Testosterone also plays a role in female sexual response, and an international consensus statement recognizes its therapeutic use in well-selected cases of low sexual desire after menopause.34
• Medications. Just as in men, SSRI antidepressants are a common medication-related cause of low libido in women.33
• Psychological, relational, and overload factors. Chronic stress, daily overload, body image, relationship quality, and mental health carry particular weight in women's complaints — which is why evaluation should never be limited to hormones alone.

The connection with weight-loss medications

This is still an area under investigation, but relevant data are already emerging. A database study of thousands of non-diabetic men with obesity found a higher risk of newly diagnosed erectile dysfunction and hypogonadism among those who used semaglutide, compared with those who did not.35 This doesn't mean the medication "causes" low libido in every patient — the mechanisms involved (effects on reward pathways, hormonal changes tied to weight loss, emotional factors) are still being studied — but it reinforces why any change in sexual desire during treatment deserves to be reported and investigated, rather than dismissed as ordinary daily stress.

When to seek medical evaluation

A temporary dip in libido, tied to a stressful or tiring phase of life, is a normal part of life. Persistent decline — lasting several months and causing personal or relationship distress — deserves investigation: hormonal evaluation, a review of current medications, screening for chronic disease, and, when indicated, psychological assessment. This isn't something to work out alone based on assumptions — it's a legitimate medical complaint, like any other.

References

1. Mitchell KR, Mercer CH, Ploubidis GB, et al. Sexual function in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Lancet. 2013;382(9907):1817-1829. pubmed.ncbi.nlm.nih.gov
2. Bhasin S, Brito JP, Cunningham GR, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. academic.oup.com
3. Kennedy SH, Rizvi S. Sexual dysfunction, depression, and the impact of antidepressants. J Clin Psychopharmacol. 2009;29(2):157-164. pubmed.ncbi.nlm.nih.gov
4. West SL, D'Aloisio AA, Agans RP, Kalsbeek WD, Borisov NN, Thorp JM. Prevalence of Low Sexual Desire and Hypoactive Sexual Desire Disorder in a Nationally Representative Sample of US Women. Arch Intern Med. 2008;168(13):1441-1449. pubmed.ncbi.nlm.nih.gov
5. Davis SR, Baber R, Panay N, et al. Global Consensus Position Statement on the Use of Testosterone Therapy for Women. J Clin Endocrinol Metab. 2019;104(10):4660-4666. pubmed.ncbi.nlm.nih.gov
6. Able C, Liao B, Saffati G, et al. Prescribing semaglutide for weight loss in non-diabetic, obese patients is associated with an increased risk of erectile dysfunction: a TriNetX database study. Int J Impot Res. 2025;37(4):315-319. pubmed.ncbi.nlm.nih.gov

This content is educational, based on international medical literature, and does not replace individual medical evaluation. Persistent loss of libido should be investigated by a physician, not addressed through assumptions or self-medication alone.