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Updated: May 29, 2026
Determination of Reproductive Competence by Confirming Pubertal Onset and Performing a Fertility Assay in Mice and Rats
Published on: October 13, 2018
Pubertal delay in male nonhuman primates (Macaca mulatta) treated with methylphenidate
Donald R Mattison1, Tony M Plant, Hui-Min Lin
1Epidemiology Branch, Division of Epidemiology, Statistics, and Prevention Research, The Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. mattisod@mail.nih.gov
Methylphenidate hydrochloride (MPH) in juvenile monkeys delayed puberty, reducing testicular volume and testosterone. However, these effects on pubertal development were not permanent, resolving by study end.
Area of Science:
- Reproductive toxicology
- Endocrinology
- Developmental biology
Background:
- Methylphenidate hydrochloride (MPH) is a widely prescribed stimulant medication.
- Concerns exist regarding its potential impact on adolescent development, particularly reproductive health.
- Long-term effects of MPH on pubertal progression require thorough investigation.
Purpose of the Study:
- To evaluate the effects of MPH on pubertal progression and testicular development in juvenile male rhesus monkeys.
- To assess potential genetic and behavioral toxicity associated with MPH treatment.
- To determine if MPH-induced pubertal alterations are reversible.
Main Methods:
- Juvenile male rhesus monkeys were administered varying doses of MPH (low and high) or vehicle orally for 40 months.
- Key parameters monitored included testicular volume, testicular descent, serum testosterone, and serum inhibin B levels.
- Statistical analyses were performed to determine significant differences between treatment groups.
Main Results:
- MPH treatment resulted in significantly reduced testicular volume and delayed testicular descent, particularly in the high-dose group.
- Both low and high doses of MPH led to significantly lower serum testosterone levels throughout most of the treatment period.
- While serum inhibin B levels were transiently increased in the low-dose group, these differences normalized by study conclusion.
Conclusions:
- Early-life exposure to MPH can impair pubertal testicular development, including volume and hormone secretion, in male rhesus monkeys.
- The observed deficits in testicular development and hormone levels appear to be reversible, with recovery noted by the end of the 40-month study.
- These findings suggest that while MPH may transiently impact pubertal progression, the effects are not permanent, though further research is needed to fully understand the long-term implications.
