For strength athletes who want to reduce their fat mass, laxogenin may be an interesting supplement. If athletes want to build more muscle mass, they may be better off using 5-alpha-hydroxy-laxogenin. This is suggested by the preliminary results of a human study, published by Dutch supplement expert Jan de Heijn. Laxogenin & 5-hydroxy-laxogenin Laxogenin and 5-alpha-hydroxy-laxogenin are steroid-like substances found in plants from the Smilax family, such as Smilax sieboldii. "Smilax supplements were already available in the 1980s," says De Heij. "But at that time companies were not yet able to extract specific substances from that plant. But that is perfectly possible now." De Heij managed to get his hands on highly purified extracts. Because there is little known about the effects of these substances, he decided to study the effects of these extracts himself and publish the results on the web. "This project is not finished yet", emphasizes De Heij. "These are the first and preliminary results." De Heij managed to get his hands on highly purified extracts. Because there is little known about the biological effects of these substances in humans, he decided to study the effects of these extracts himself and to publish the results on the web. "This project is not finished yet", emphasizes De Heij. "These are the first and preliminary results." Study For his research, De Heij cooperated with a Dutch gym. De Heij supplied supplements containing per capsule or nothing at all, or 24 milligrams of laxogenin or 22 milligrams of 5-alpha-hydroxy-laxogenin. Experienced strength athletes who wanted to participate in the study took 2 capsules every day for 4 weeks. The study was double-blind. The athletes did not know what they were using, nor did the person who handed out the supplements. Results Maximum strength increased in all groups, but the subjects who had used 5-alpha-hydroxy-laxogenin did better than the other two groups. Muscle size also increased in all groups of subjects, as you can see above. [Omtrek bovenarm = mid upper arm circumference.] Again, the increase seemed to be the greatest among the subjects who had used 5-alpha-hydroxy-laxogenin. Fat percentage decreased in the laxogenin group only. [Vetpercentage = fat percentage.] In the other two groups, fat percentage remained more or less stable. Conclusion De Heij's data are still raw. Statistical calculations, which tell us whether the associations are significant, have not yet been carried out. Nevertheless, they suggest that laxogenin has a different effect than 5-alpha-hydroxy-laxogenin. Laxogenin emerges from the data as a fat loss supplement, while 5-alpha-hydroxy-laxogenin appears to have an anabolic effect.