Selective Androgen Receptor Modulators (SARMs) have gained popularity in fitness communities as an alternative to anabolic steroids, primarily for their muscle-building effects. This rise in use, particularly among younger individuals, has led to questions about their impact on skeletal development, specifically height. The concern centers on whether these compounds can unnaturally promote height growth or, more dangerously, prematurely stop it by interfering with the body’s natural growth mechanisms.
Understanding SARMs and Their Function
SARMs are a class of synthetic drugs designed to selectively stimulate androgen receptors (AR) found in the body. These receptors are the targets of male hormones like testosterone. By activating these receptors, SARMs can promote anabolic activity, such as increased muscle mass and bone density. The goal of developing SARMs was to harness the beneficial effects of androgens on muscle and bone while minimizing unwanted side effects on other tissues, such as the prostate.
SARMs are being investigated in medical research for conditions involving muscle wasting or bone weakness, like cancer-related cachexia, osteoporosis, and frailty. The selectivity they offer is meant to make them a safer alternative to non-selective anabolic steroids. However, SARMs are not approved by the Food and Drug Administration (FDA) for human use and are often sold illegally as “research chemicals”.
The Process of Skeletal Height Growth
Height increase in humans is determined by the lengthening of long bones, such as those in the arms and legs. This process occurs at specialized areas of cartilage near the ends of these bones called epiphyseal plates, or growth plates. While these plates are open, cartilage cells continuously multiply, mature, and are replaced by new bone tissue in a process called endochondral ossification. This replacement pushes the ends of the bone further apart, resulting in longitudinal growth.
The timing of growth plate activity is tightly regulated by a complex interplay of hormones, including growth hormone (GH), insulin-like growth factor-I (IGF-I), and sex steroids. Puberty marks the final phase of this process, during which an increase in sex hormones signals the eventual end of growth. For boys, growth plates typically close between 16 and 18, while for girls, closure usually occurs earlier, between 14 and 16.
The permanent cessation of height growth happens when the cartilage in the growth plates is entirely replaced by solid bone, a process known as epiphyseal fusion. Once this fusion is complete, the bones can no longer lengthen, and an individual’s final adult height is reached. The primary hormonal driver for this final closure in both sexes is estrogen, which is either produced directly or converted from androgens like testosterone.
SARMs and Growth Plates: The Biological Interaction
The question of whether SARMs affect height is directly linked to their interaction with the growth plates. Since SARMs are selective androgen receptor modulators, they function by engaging the same hormonal pathways that regulate bone growth and maturation. When SARMs activate androgen receptors in bone tissue, they stimulate anabolic activity and accelerate skeletal maturation.
The danger of SARMs to height lies in their potential to accelerate epiphyseal fusion. Androgens, including those mimicked by SARMs, can be converted into estrogen, or they can directly influence the growth plate. Exposing a still-growing adolescent to high levels of these compounds is likely to mimic the late-pubertal hormonal surge that signals the growth plates to close.
This premature closure means the individual’s long bones stop lengthening earlier than they naturally would, resulting in a permanent stunting of potential adult height. SARMs cannot make a skeletally mature adult taller because the growth plates have already fused. For an individual whose growth plates are still open, the most probable outcome of SARM use is the premature end of their height growth, not an increase in height.
Legal Status and Unregulated Risks
Beyond the specific risk to skeletal development, SARMs carry substantial safety concerns due to their unregulated status. These compounds are not approved by the FDA for human consumption and are often marketed illegally as dietary supplements or “research chemicals”. This lack of regulatory oversight means that the purity, dosage, and actual ingredients of products sold online are often unreliable.
Analysis of these unregulated products has frequently found inaccurate labeling, with some containing no SARM at all, or worse, containing unlisted, harmful substances, including traditional anabolic steroids. The use of SARMs is associated with serious adverse health events, such as an increased risk of heart attack, stroke, and drug-induced liver injury. Consumers who use these unapproved drugs are exposed to unknown long-term health consequences and immediate threats.