Ashwagandha (Withania somnifera) is a small evergreen shrub whose root has been used for thousands of years in Ayurvedic medicine. This herb is classified as an adaptogen, meaning it is thought to help the body resist and manage stress. This classification has led to interest in its potential for health concerns, including hair loss often linked to chronic stress and hormonal imbalance. This article explores the connection between stress and hair health, the mechanism by which Ashwagandha is believed to act, and what current scientific evidence says about its effectiveness for hair growth.
Stress and Hormones as Hair Loss Triggers
The body’s response to prolonged stress involves activating the Hypothalamic-Pituitary-Adrenal (HPA) axis. When this axis is constantly engaged, it leads to the sustained overproduction of stress hormones, particularly cortisol. High levels of circulating cortisol disrupt the normal hair growth cycle, which includes the growth phase (anagen), transitional phase (catagen), and resting/shedding phase (telogen).
Chronic stress can prematurely signal hair follicles to exit the active anagen phase and enter the resting telogen phase, resulting in a condition known as Telogen Effluvium. This condition typically becomes noticeable two to four months after a significant stressful event. Furthermore, the hormone Corticotropin-releasing hormone (CRH), released early in the HPA axis cascade, has been shown to inhibit hair growth directly.
Ashwagandha’s Role in Modulating Body Stress
Ashwagandha’s reputation as an adaptogen is tied to its ability to modulate the HPA axis. Supplementation can lead to a significant reduction in serum cortisol levels. This cortisol-lowering effect is the primary mechanism by which the herb is believed to support a healthier environment for hair growth.
The plant’s beneficial effects are attributed to withanolides, a group of naturally occurring compounds. These withanolides are thought to interact with neuroendocrine pathways, dampening HPA axis activity. By regulating this hormonal environment, Ashwagandha may help regulate the hormonal environment that can trigger stress-induced hair shedding.
Dosages that successfully lowered cortisol in human studies are generally 300 to 600 milligrams of standardized root extract per day, taken over several weeks or months. The reduction of chronic physiological stress may allow hair follicles that were prematurely forced into the resting phase to return to the active growth phase. This mechanism supports the idea that Ashwagandha may help prevent or reverse hair loss specifically due to chronic stress or high cortisol.
Scientific Consensus on Hair Growth Efficacy
While evidence for Ashwagandha’s ability to reduce stress and lower cortisol is strong, the scientific literature specifically linking its oral consumption to stopping hair loss or promoting hair regrowth is limited. Claims regarding hair benefits often stem from the logical assumption that less stress equals less stress-induced hair loss. High-quality, large-scale human clinical trials confirming a direct hair growth effect from systemic supplementation are largely absent.
The focus of most robust research has been on anxiety, stress, and sleep, which are related conditions. Therefore, it is difficult to state that taking Ashwagandha capsules will stop hair loss caused by factors other than stress, such as genetic or autoimmune conditions.
However, a recent randomized controlled study investigated the effects of a topical Ashwagandha root extract serum on hair health. This study, involving participants with mild-to-moderate hair loss, reported significant improvements in several hair health indicators over a 75-day period. The topical Ashwagandha group showed enhanced hair density, increased speed of hair growth, and a reduction in hair shedding compared to the placebo group.
This finding suggests that Ashwagandha may contain compounds that benefit the hair follicle directly. The topical application may deliver active ingredients directly to the hair follicle. While promising, this single study on topical application does not confirm the effectiveness of consuming oral Ashwagandha for hair growth.
Safe Usage and Consumption Forms
Ashwagandha is most commonly consumed in the form of capsules, powder, or liquid tincture. When choosing a supplement, look for products standardized to contain a specific percentage of withanolides, as these are the primary active compounds.
Typical dosages for standardized root extracts are 300 to 600 milligrams taken once or twice daily. Ashwagandha is generally well-tolerated, but large doses may cause mild side effects such as stomach upset, diarrhea, or drowsiness.
The herb is not safe for everyone, and certain individuals should consult a healthcare provider first. Ashwagandha may increase thyroid activity. It should also be avoided by individuals who are:
- Pregnant or breastfeeding.
- Taking thyroid medication or have hyperthyroidism.
- Dealing with autoimmune diseases, such as lupus or rheumatoid arthritis, because it may stimulate the immune system.