Laxogenin is not a Selective Androgen Receptor Modulator (SARM). The confusion is understandable because both compounds are frequently discussed in fitness circles for their purported abilities to enhance muscle growth and athletic performance. While both are associated with anabolic effects, they belong to entirely different chemical classes and operate through distinct biological mechanisms. Understanding these fundamental differences, from their origin to their regulatory status, clarifies why Laxogenin cannot be classified alongside SARMs. The key distinction lies in how each compound interacts with the body’s hormonal signaling pathways.
Defining Selective Androgen Receptor Modulators
Selective Androgen Receptor Modulators are synthetic compounds developed to produce anabolic effects similar to traditional anabolic steroids. They are structurally designed to be non-steroidal, aiming to separate muscle-building effects from unwanted androgenic side effects. SARMs achieve their effect by acting as ligands, binding directly to the body’s androgen receptors (AR) in a tissue-selective manner.
This tissue selectivity is the defining characteristic of SARMs, activating the AR primarily in skeletal muscle and bone tissue. This minimizes activation in tissues like the prostate, reducing the risk of side effects such as prostate enlargement or acne. Once bound, the SARM-AR complex moves into the cell nucleus, regulating the transcription of genes responsible for muscle protein synthesis and bone density.
SARMs are fundamentally hormonal agents because they directly engage the androgen receptor pathway. This engagement means they carry the risk of suppressing the body’s natural production of testosterone by interfering with the hypothalamic-pituitary-gonadal (HPG) axis. Currently, all SARMs are considered investigational drugs and have not been approved for human use by regulatory bodies like the U.S. Food and Drug Administration (FDA).
Understanding Laxogenin
Laxogenin (5-alpha-hydroxy-laxogenin) is a naturally occurring plant sterol, placing it in a different category from synthetic SARMs. This compound is isolated from the root and rhizomes of plants like Smilax sieboldii. Laxogenin is categorized as a brassinosteroid, a class of polyhydroxylated steroids found in plants that function as growth hormones.
Brassinosteroids promote growth and vitality in the plants where they are found. When adapted for human use, Laxogenin is promoted as a non-hormonal compound. It is generally sold as a dietary supplement ingredient, marketed to consumers seeking muscle-building and recovery benefits. Laxogenin is not intended to interact with the human endocrine system or sex hormones.
The Key Difference in Biological Mechanism
The most significant distinction lies in their respective mechanisms of action and relationship to the androgen receptor (AR). SARMs function by directly binding to the AR, acting as a direct agonist to signal muscle growth. This direct interaction defines a SARM and is responsible for its systemic effects, including potential hormonal suppression.
Laxogenin’s proposed mechanism is entirely independent of the AR pathway, classifying it as a non-hormonal agent. It is believed to exert its anabolic effects through pathways that regulate protein synthesis and breakdown. A primary proposed mechanism involves upregulating the Akt/mTOR signaling pathway, a master regulator of cell growth and metabolism.
Laxogenin may also act by inhibiting the activity of myostatin (MSTN), a protein that naturally restricts muscle growth. Suppressing this negative regulator could theoretically remove a brake on muscle development. This non-AR-mediated mechanism is why Laxogenin is touted as lacking the hormonal side effects associated with SARMs, such as testosterone suppression.
Regulatory Status and Classification
The regulatory status highlights the stark difference in classification for consumer use. SARMs are not approved for consumption and are considered unapproved new drugs by the FDA. The FDA has issued warnings regarding the serious health risks associated with their use, including liver toxicity and cardiovascular issues.
For competitive athletes, SARMs are explicitly prohibited at all times by the World Anti-Doping Agency (WADA) and the U.S. Anti-Doping Agency (USADA), listed under the category of S1 Anabolic Agents. This classification reflects their powerful anabolic properties and hormonal mechanism. Laxogenin, conversely, is generally sold legally as a dietary supplement ingredient derived from a plant extract.
DoD Status
While Laxogenin is commonly available through the supplement market, athletes should exercise caution as the U.S. Department of Defense (DoD) Prohibited Dietary Supplement Ingredients list includes 5-alpha-hydroxy-laxogenin. The regulatory freedom of Laxogenin stems from its classification as a plant sterol, but SARMs are strictly prohibited due to their synthetic nature, direct hormonal action, and status as unapproved investigational drugs.