Traditionally, Tongkat Ali is one of the oldest and most popular testosterone support ingredients in existence. Eurycoma longifolia is a plant native to Malaysia, Indonesia, and Thailand which has been used in traditional remedies for centuries. This plant has a multitude of nicknames including Tongkat Ali, Long Jack, Malaysian Ginseng, and Walking Stick. The list of purported traditional benefits is even longer than the list of nicknames, although it’s proposed effects for supporting testosterone levels are arguably the most popular.
An issue that arises with herbs rumored to have promising effects is that often there’s a lack of consistency from batch to batch, likely due to inconsistencies with bioactive compounds among batches. The popularity of Tongkat prompted the Malaysian government to thoroughly investigate its potential benefits. It was the collaboration between the Malaysian government and MIT that resulted in LJ100. LJ100® is a patented version of Tongkat that has isolated the bioactive eurypeptides, and has been extensively tested in humans with encouraging results.
A number of human studies conducted on LJ100 have found it to have promising potential across a variety of positive measures. These findings demonstrate that Tongkat Ali has beneficial anabolic properties, which can be utilizedby athletes across a variety of sports.
A pilot study investigated the ergogenic potential of Tongkat Ali among an active, elderly population. The study had 25 physically active male and females supplement with Tongkat Ali for five weeks. At the end of the study, the researchers noted significant increases in total and free testosterone as well as muscle force in both genders. 
A study examined the effects of Tongkat Ali supplementation on stress hormones and psychological mood state. The researchers split 63 subjects (32 men and 31 women) into two groups. Over the course of four weeks, one group supplemented with 200 mg/ day of Tonkgat Ali, while the other group used a placebo. At the end of the study, the researchers saw reduced cortisol levels, increased testosterone status, and an overall improvement in the cortisol:testosterone ratio in the Tongkat Ali group.
A pilot study was conducted on 14 healthy men undergoing a strength training routine whereby half of them supplemented with Tongkat Ali and half received a placebo. The subjects followed a circuit training routine for a total of five weeks. At week one, they performed 2 sets of 10 at 60% of their 1RM at ten different exercise stations, then increased the intensity by 10% each week. While both groups made significant strength gains, the Tongkat Ali group demonstrated a greater percentage increase in strength compared to the placebo group (6.78% and 2.77% respectively). 
A study was done to determine the effects of Tongkat Ali on testosterone and cortisol levels during intense endurance events. Thirty male subjects participating in a 24-hour mountain biking event were assessed, whereby half of them received a placebo and half supplemented with Tongkat Ali 30 minutes prior to the event. The researchers saw lower cortisol levels and higher testosterone levels in the group that supplemented with Tongkat Ali. 
A 12-week study was done on 31 women to examine the effects that Tongkat Ali had on physical function and muscle size. One group supplemented with a placebo and the other group supplemented with Tongkat Ali. Both groups did two strength training sessions a week consisting of work done at 60% of their 1RM. Both groups saw significant improvements in their leg press and bench press numbers, but the group that supplemented with Tongkat Ali showed increased muscle endurance and muscle size. 
While there are a few hormonal responses with supplementation of Tongkat, the precise details as to how and why it works are still relatively unclear. LJ100 may increase the bioavailability of testosterone by lowering the amount of sex hormone binding globulin (SHBG) in the blood. LJ100 may also be involved in reducing the conversion of testosterone to estrogen, balancing the supply of this anabolic hormone. Tongkat also contains eurypeptides that have been proposed to activate an enzyme which increases the biosynthesis of testosterone. This has led some scientists to suggest that Tongkat acts more as a testosterone “maintainer” rather than a booster as it helps maintain levels within the normal range.
From the studies on LJ100, it’s most promising effects revolve around its ability to promote a favorable hormone profile. Males who are 30 years old and older would likely see the most benefits, but Tongkat studies have shown benefits among both genders.
Ferodrox is one of your best sources to get LJ100. Ferodrox contains 200 mg of LJ100. This dosage was commonly used in many of the studies which found Tongkat to be significantly effective. Ferodrox also contains other scientifically tested ingredients including KSM-66® Ashwaghanda and PrimaVIe® ShilaJit, which have also been found to have positive scientific research findings.