Background: It has been suggested that supplementation with Tongkat Ali may affect testosterone concentrations; moreover, whether this influences body composition is unclear. Thus, the purpose of this investigation was to determine if four weeks of Tongkat Ali (400 mg daily dose) supplementation affected body composition and salivary free testosterone concentrations. Methods: Thirty-three exercise-trained males (n = 19) and females (n = 14) volunteered for this investigation (mean ± standard deviation: age 33.1 ± 13.0 years; height 171.1 ± 11.3 cm; body mass 77.4 ± 16.8 kg; average total years of training 13.9 ± 13.2; average hours of resistance training/week 4.2 ± 2.5; average hours of aerobic exercise/week 3.4 ± 2.8; average hours of other exercise/week 1.1 ± 2.0). Research participants were pre- and post-tested for body composition (InBody 270), Profile of Mood States (POMS), handgrip strength, and sleep (Pittsburgh Sleep Quality Index [PSQI]). In a subset of the research participants, saliva samples were collected and analyzed for cortisol and free testosterone. The research participants consumed 400 mg of Tongkat Ali or a placebo (rice flour) daily for four weeks. Results: There were no between-group differences (p > 0.05) for body composition (delta score, mean ± SD: lean body mass kg-treatment −0.5 ± 1.9, placebo −0.4 ± 0.7; fat mass kg-treatment −0.5 ± 1.6, placebo 0.3 ± 1.0, % fat treatment −0.1 ± 1.4, placebo 0.5 ± 1.1). Moreover, there were no differences between groups for any additional assessments (e.g., handgrip strength, mood, sleep, and salivary free testosterone and cortisol). Conclusions: Four weeks of supplementation with Tongkat Ali in exercise-trained males and females does not affect body composition, mood, sleep, vigilant attention, handgrip strength, cortisol, and free testosterone.