TestoJack 300™ – Bioavailability Study

Bioavailability Study

TestoJack 300™ is a standardized extract of Tongkat Ali (or Long Jack) used to support male reproductive function.* Two healthy male volunteers, 57 and 58 years old, took TestoJack 300™, a dietary supplement by NOW Foods® (Product # 2202), 2 capsules after breakfast for 4 weeks without dietary and lifestyle modifications. Total and free testosterone was measured at the baseline, and after 2 and 4 weeks of supplementation.


At the end of the observation period, total testosterone increased 64% and 17% above the baseline level for volunteer 1 and 2, respectively (Figure 1).* During the same period, free testosterone rose 59% and 62% (Figure 2).* The case study indicates that supplementation with TestoJack 300™ in these healthy adult males was effective in supporting testosterone levels within the normal range.* Interpretation of the results is limited due to the observational nature of the case study.

Figures 1 and 2: In an observational case study conducted with two healthy male volunteers (57 and 58 years old), supplementation with TestoJack 300™ (2 capsules after breakfast for 4 weeks, NOW® product # 2202) resulted in support of already normal total and plasma testosterone.*

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.