Ashwagandha (Withania somnifera) is an adaptogenic herb revered in Ayurveda, the traditional Indian system of medicine. Practitioners have used its roots for thousands of years to promote general wellness and help the body adapt to stress. A popular claim suggests the herb might promote linear growth and increase adult height, often linked to its purported influence on hormonal systems related to growth.
Biological Factors Determining Adult Height
A person’s final height is determined by a complex interplay of genetic factors, nutrition, and endocrine signaling during childhood and adolescence. Linear growth occurs primarily at the ends of the long bones, within structures called epiphyseal plates, or growth plates. These plates consist of cartilage cells that divide and are replaced by hardened bone tissue, causing the bone to lengthen.
The function of these plates is regulated by hormones, particularly human growth hormone (HGH) and insulin-like growth factor 1 (IGF-1). Once an individual reaches skeletal maturity, typically in late adolescence or early adulthood, the cartilage in these growth plates fully ossifies and fuses into solid bone. After this fusion, no further increase in linear height is biologically possible.
Proven Mechanisms of Ashwagandha Action
Scientific research validates Ashwagandha’s primary role as an adaptogen, helping the body resist physical and chemical stressors. Its most established mechanism involves regulating the hypothalamic-pituitary-adrenal (HPA) axis, the body’s central stress response system. By modulating this pathway, Ashwagandha significantly lowers the concentration of the stress hormone cortisol in the blood, an effect consistently demonstrated in human trials.
This reduction in chronic stress can have minor, indirect effects on other endocrine functions. Supplementation has been observed to increase levels of dehydroepiandrosterone-sulfate (DHEA-S) and, in men, modest increases in testosterone. This hormonal modulation is generally considered a secondary benefit resulting from better stress management, not a direct action of growth promotion. The active compounds, known as withanolides, offer anti-inflammatory and antioxidant support.
Scientific Evidence on Height Increase
Despite its traditional use, there is currently no credible scientific evidence demonstrating that Ashwagandha can increase height in adults. The closure of the epiphyseal plates is a fundamental biological constraint, making linear growth impossible once skeletal maturity is reached. No supplement, including Ashwagandha, can reverse the fusion of these growth plates.
For adolescents whose growth plates have not yet fused, the herb’s potential to reduce stress may indirectly support optimal growth conditions. Chronic, excessive stress and elevated cortisol levels are known to negatively impact the hormonal signals that drive growth. By mitigating this stress, Ashwagandha could theoretically help the body maintain an environment conducive to reaching its genetically predetermined height potential. This effect is supportive only; it does not introduce a new mechanism for growth and cannot override the substantial influence of genetics and childhood nutrition.
Dosage and Safety Considerations
For individuals seeking proven benefits like stress reduction and improved strength, typical dosages range from 250 to 600 milligrams of standardized root extract per day. These amounts are generally well-tolerated in the short term, often for periods of up to three months. It is important to look for products independently verified for purity and potency, as the supplement industry lacks rigorous regulation.
Some individuals may experience mild side effects, including digestive upset, diarrhea, or drowsiness. Ashwagandha is not safe for everyone and carries warnings for specific populations. Pregnant or breastfeeding individuals should avoid the supplement, and those with autoimmune diseases should use caution due to its potential to stimulate the immune system. The herb can also interact with medications for diabetes, high blood pressure, and thyroid conditions, requiring medical consultation before use.