Does Modafinil Affect Sex Drive?

Modafinil has been linked to changes in sexual desire and sexual function, but the evidence is limited. Published reports mostly describe increased desire, improvement in pre-existing sexual dysfunction, or hypersexuality during extreme overuse.

There are no large controlled trials designed specifically to determine whether modafinil raises or lowers libido. Most of the direct evidence comes from individual cases involving people who already had sexual problems, including sexual dysfunction associated with antidepressants.

Can Modafinil Increase Sex Drive?

Bhattacharjee and Mahato (2025) described two men who reported improvements in sexual desire after taking modafinil.

One was a 28-year-old man being treated for depression. Reduced sexual desire was already one of his symptoms, and his libido worsened after his sertraline dose was increased from 100 to 200 mg. He began taking 100 mg of modafinil once or twice a week and reported improved sexual desire.

A second case involved a 32-year-old man with hypothyroidism who had reduced sexual desire and erectile difficulty. He began taking 100 mg of modafinil daily and reported improvement in his sexual symptoms.

Both cases are heavily confounded: depression, sertraline and hypothyroidism can all affect sexual function, and neither case included a placebo or other control. The reports show that increased sexual desire after modafinil has occurred, but they cannot establish that modafinil caused the change.

Can Modafinil Improve Antidepressant-Related Sexual Dysfunction?

Yilbaş (2022) described two women who developed sexual problems during antidepressant treatment despite improvement in their depression.

Both reported loss of sexual desire, reduced arousal and difficulty reaching orgasm after starting antidepressants. Neither had reported sexual dysfunction before treatment.

The first woman, aged 39, received modafinil at 100 mg per day, primarily for daytime sleepiness. After one month, she reported marked improvement in sexual desire, arousal and orgasm.

The second woman, aged 43, had only slight improvement at 100 mg per day. Her dose was increased to 200 mg per day, after which the authors reported greater improvement in her sexual symptoms.

These cases may represent improvement in antidepressant-associated sexual dysfunction rather than an increase in libido above the women’s normal baseline.

Two uncontrolled cases are not enough to establish modafinil as a treatment for antidepressant-related sexual dysfunction.

Can Modafinil Cause Hypersexuality?

Sahoo et al. (2016) reported hypersexual behaviour in a 35-year-old man who had escalated his modafinil intake to approximately 800 to 1,000 mg per day.

At these doses, he developed spontaneous erections around women, masturbated as often as 10 to 12 times per day, became preoccupied with sexual fantasies and experienced increased urges to seek sexual contact outside his marriage.

The patient had bipolar disorder, but the authors reported no evidence that the sexual behaviour was part of a manic or hypomanic episode. He did not show the other features that had accompanied his previous manic episodes, and hypersexuality had not been a feature of those episodes.

His hypersexual symptoms decreased substantially as modafinil was gradually reduced.

This case involved extreme modafinil overuse and cannot be generalised to standard therapeutic doses. It does show that pronounced changes in sexual behaviour have occurred in association with very high modafinil exposure.

Why Might Modafinil Affect Sexual Desire?

Volkow et al. (2009) found that modafinil affects dopamine signalling: in 10 healthy men given 200 or 400 mg, it occupied dopamine transporters and increased extracellular dopamine in several brain regions, including the nucleus accumbens.

The nucleus accumbens plays an important role in reward and motivated behaviour, while dopamine is involved in sexual motivation and reward-seeking. These findings provide a plausible biological route through which modafinil could influence sexual desire or behaviour.

Volkow et al. did not measure libido, sexual performance or sexual behaviour. The study supports a possible mechanism, not evidence that modafinil increases sex drive.

Can Modafinil Lower Sex Drive?

Published clinical reports provide little direct evidence that modafinil lowers libido. The available case literature does not establish decreased sexual desire as a recurring reported effect.

Modafinil Dependence After Self-Medicating Sexual Problems

Bhattacharjee and Mahato (2025) described three people who began using modafinil in response to sexual problems and later developed modafinil dependence.

The 28-year-old man who initially used 100 mg intermittently for reduced sexual desire eventually progressed to a total daily intake of 800 mg.

A 34-year-old woman began taking 100 mg before sexual activity after escitalopram caused difficulty reaching orgasm and vaginal dryness. Lubricants helped the dryness but not the orgasm difficulty. Her modafinil use subsequently escalated to 1,000 mg per day.

The 32-year-old man who initially used modafinil for reduced sexual desire and erectile difficulty eventually reached 900 mg per day.

Across the cases, the authors described tolerance, craving, impaired control over use and withdrawal symptoms. Increasing doses were required to reproduce the effects the patients had come to expect.

These cases do not show that sexual effects commonly lead to modafinil dependence. They do show that repeatedly self-medicating sexual problems with modafinil can become associated with severe dose escalation and dependence in individual cases.

Bottom Line

Modafinil is not established as a general libido enhancer. The published cases suggest that sexual effects can occur, but the more consequential safety finding is that some people who used modafinil to self-medicate sexual problems escalated to very high doses and developed dependence.

References

Bhattacharjee, D., & Mahato, S. K. (2025). Development of modafinil dependence following self-medication for sexual dysfunction: A case series. Indian Journal of Psychological Medicine, 47(2), 190–192. https://doi.org/10.1177/02537176231200185

Sahoo, S., Subodh, B. N., & Gupta, G. (2016). Modafinil dependence and hypersexuality: A case report and review of the evidence. Clinical Psychopharmacology and Neuroscience, 14(4), 402–404. https://doi.org/10.9758/cpn.2016.14.4.402

Volkow, N. D., Fowler, J. S., Logan, J., Alexoff, D., Zhu, W., Telang, F., Wang, G.-J., Jayne, M., Hooker, J. M., Wong, C., Hubbard, B., Carter, P., Warner, D., King, P., Shea, C., Xu, Y., Muench, L., & Apelskog-Torres, K. (2009). Effects of modafinil on dopamine and dopamine transporters in the male human brain: Clinical implications. JAMA, 301(11), 1148–1154. https://doi.org/10.1001/jama.2009.351

Yilbaş, B. (2022). Could modafinil be an option in the treatment of sexual dysfunctions due to antidepressant use in women? Two case reports. Turkish Journal of Psychiatry, 33(3), 206–210. https://doi.org/10.5080/u25974