Tongkat Ali (Eurycoma longifolia), also known as longjack, is a root native to Southeast Asia and one of the more studied herbal ingredients in the male vitality category. Here's what current research actually shows.
Testosterone
Several studies have looked at Tongkat Ali's effect on testosterone, particularly in men with clinically low levels. One frequently cited 2012 study of 76 older men with low testosterone found that 200 mg of Tongkat Ali extract per day significantly raised testosterone to normal values in the large majority of participants. Other research suggests it may help increase free testosterone specifically. That said, while the direction of evidence is encouraging and the proposed mechanisms are plausible, researchers note the overall body of data isn't yet considered conclusive.
Libido and Stress
Tongkat Ali is also studied for its effect on cortisol, the body's primary stress hormone — several trials suggest it may help lower cortisol, which could indirectly support testosterone production and mood. Libido and mood improvements tend to show up more consistently in the research than dramatic changes in muscle mass or strength.
Typical Dosage
For libido and general vitality support, studies commonly use 200–400 mg per day, sometimes split into one or two doses. As always, follow the amount specified on the product label you're using rather than assuming more is better.
Tongkat Ali may not be appropriate for everyone, including those with hormone-sensitive conditions. Talk to a healthcare provider before starting it, especially if you take other medications.
Where It Shows Up
Tongkat Ali is one of seven ingredients in HorseWood's formula, alongside Saw Palmetto, Horny Goat Weed, Wild Yam, Nettle Leaf, Sarsaparilla, and Boron.
See Tongkat Ali in a Full Formula
Check the exact dose and full ingredient panel in HorseWood.
View HorseWoodSources: Healthline, Examine.com, NCBI/PMC.