Faith Holland, Ookie Canvases, 2015
The fertility signal is real, but small enough to be reassuring, and only one stimulant is implicated
STUDY: Siva J et al, IJIR: Your Sexual Medicine Journal 2026;
STUDY TYPE: Retrospective matched cohort study
FUNDING: Independent
Background
Stimulant prescriptions for adult men with ADHD have climbed steadily over the past decade. As more reproductive-age men take these medications long-term, a practical question has emerged: do stimulants affect sperm?
The Study
- 388 men with ADHD who had an active stimulant prescription within 90 days of semen analysis, matched 2:1 to 776 stimulant-unexposed men with ADHD.
- Ages 18–40; median age 33 in both groups; drawn from two tertiary care centers over 30 years.
- Men with varicocele, cryptorchidism, diabetes, prior hormonal treatments, or other known fertility confounders were excluded.
Stimulant-exposed men had modestly lower semen volume than controls (2.70 mL vs. 2.95 mL). After adjusting for age, abstinence time, and calendar year, stimulants were associated with an 8.4% lower semen volume. The absolute difference was just 0.25 mL.
No other semen parameters differed between groups. Sperm concentration, motility, total sperm count, and total motile sperm count were essentially identical. The proportion of men with very low semen volume (under 1 mL) was similar in both groups (5.9% vs. 5.0%).
In a subgroup analysis by drug class, amphetamines drove the volume difference. Methylphenidate users showed no significant difference from controls.
Why?
We don’t know. But testosterone may explain some of this. A recent study linked amphetamines (but not methylphenidate) to lower testosterone, although the link is not confirmed. Testosterone is required for the secretory function of the seminal vesicles and prostate, which produce the bulk of seminal fluid.
Limitations
Retrospective design; no data on dose, duration, or adherence; single time-point semen samples; cohort skews toward men already seeking fertility evaluation.
Practice Implications
- Some caution, some reassurance here. There is a slight drop in ejaculate volume with stimulants, but no effect on sperm quality, and that’s what matters for conception.
— Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
