© Freepik
March 29, 2026
Marianne Waldenfels
Ashwagandha may increase testosterone by 10–20%—but not as much as often claimed. Learn what studies show, how it works, and who may benefit
Find a DoctorSearch the network for suitable specialists and contact them directly
Ashwagandha is often promoted as a natural testosterone booster – sometimes with astonishing promises. More energy, more muscle growth, higher hormone levels: Expectations are high.
But what of this actually stands up to scientific scrutiny?
Studies now show quite clearly: Ashwagandha can increase testosterone levels in men. The effect is real – but significantly more moderate than many assume. How strong it is depends crucially on who takes the supplement and under what conditions.
Ashwagandha can moderately increase testosterone levels in men, usually in the range of about 10 to 20 percent. The effects are particularly pronounced in men with increased stress, overweight, or impaired fertility. In healthy men with normal baseline levels, the increase is generally lower and is not a substitute for medical testosterone therapy.
Ashwagandha (Withania somnifera) is a central component of Ayurvedic medicine and is traditionally used as a so-called adaptogen – a substance that is intended to help the body better cope with stress.
In recent years, interest in Ashwagandha has shifted significantly towards its potential hormonal effects. It is often marketed as a "natural testosterone booster," particularly in the context of male health, performance, and muscle building.
However, scientific evidence indicates: If Ashwagandha influences testosterone, it is likely not through direct hormonal stimulation, but rather through several indirect pathways.
A central focus is stress regulation. Several studies show that Ashwagandha can lower cortisol levels. Since chronically elevated cortisol levels can impair the hypothalamic-pituitary-gonadal axis, a reduction in stress hormones could indirectly lead to higher testosterone levels.
Additionally, there are effects on physical performance and recovery. In intervention studies, not only muscle strength and muscle mass improved under Ashwagandha, but also parameters like VO₂max. These changes are often associated with a more favorable hormonal environment.
Furthermore, there is evidence that Ashwagandha influences other hormonal systems – such as DHEA-S or thyroid hormones like T3 and T4. These could also indirectly modulate androgen status.
However, it is important: None of these hypotheses demonstrate a strong, direct testosterone stimulation. Rather, everything points to a regulatory, adaptogenic effect on.
A particularly often-cited experiment investigated 57 healthy men who completed a structured strength training over eight weeks. The participants received either 600 mg of Ashwagandha extract daily or a placebo.
The result: The Ashwagandha group made significantly greater progress in muscle strength and muscle mass. At the same time, testosterone levels also increased significantly more than in the control group.
The interpretation is close, but not trivial: Whether the increase in testosterone is a direct effect of the extract or rather a result of improved training adaptation cannot be definitively determined.
A different picture emerges in older, overweight men. In a 16-week crossover study, Ashwagandha increased testosterone levels by about 14.7 percent and DHEA-S by about 18 percent. However, these effects disappeared after discontinuation – indicating that the effect is not sustainable.
In highly stressed adults, there was a consistent decrease in cortisol levels and an improvement in subjective stress symptoms. The increase in testosterone was measurable here, but not statistically significant compared to placebo.
The effects are most pronounced in a specific patient group: men with oligospermia. In several studies, both sperm parameters and testosterone and LH levels improved. Here, Ashwagandha appears to actually induce clinically relevant hormonal changes.
Under real-world conditions, the testosterone effect of Ashwagandha is best described as moderate. In many studies, the increase is in the range of about 10 to 20 percent.
For men with unfavorable baseline conditions – such as chronic stress, overweight, or reduced fertility – this can be quite noticeable. In healthy men with normal hormone levels, however, the effect is usually limited.
It is also crucial to consider the context: Ashwagandha does not act like a pharmacological intervention, but rather as a supportive factor in the interplay of training, recovery, and stress management.
Most clinical studies use dosages of about 600 mg of a standardized root extract per day, divided into two individual doses.
The duration of intake is typically between eight and twelve weeks. In longer studies, it is shown that hormonal effects subside after discontinuation – an indication that continuous intake is necessary to maintain the effect.
Another important point is the quality of the extract. Since studies often refer to specific, standardized preparations, the results cannot be readily transferred to any product.
The current data suggests that Ashwagandha is well tolerated in usual dosages for healthy adults. Occasionally, mild side effects such as gastrointestinal complaints or fatigue are reported.
However, caution is advised in certain pre-existing conditions, especially thyroid or autoimmune diseases. Simultaneous use of medication should also be medically clarified.
Long-term data over very long intake periods is still limited.
Studies suggest that especially men with high stress levels, limited recovery, or suboptimal hormone levels could benefit from Ashwagandha.
In the context of strength training, the extract can also play a supportive role by improving adaptation processes and possibly slightly increasing testosterone levels.
Ashwagandha is less suitable for men with clinically relevant hypogonadism who need targeted hormonal therapy. It also does not meet expectations for rapid or strong testosterone increases.
Ashwagandha can increase testosterone – several clinical studies and meta-analyses consistently show this. However, the effect is moderate and highly context-dependent.
Its greatest strength probably does not lie in a direct hormone increase, but in the combination of stress reduction, improved recovery, and positive effects on performance and fertility.
Thus, Ashwagandha is less of a “natural anabolic” and more of an adaptogenic supporter that, in certain situations, can make a measurable but limited contribution to hormonal balance.
Yes, Ashwagandha can increase testosterone levels in men. Studies generally show a moderate increase of about 10 to 20 percent, especially in cases of stress, overweight, or fertility issues.
Most studies used about 600 mg daily, usually divided into two doses. It's crucial to use a standardized extract, as quality can vary greatly.
A measurable effect usually appears after 8 to 12 weeks. Short-term effects within a few days are unlikely.
Yes, Ashwagandha can help increase testosterone naturally, primarily by reducing stress and improving recovery. However, the effect remains moderate.
In healthy men with normal testosterone levels, the effect is usually less pronounced. More noticeable changes are seen with unfavorable baseline levels.
Ashwagandha is one of the better-researched herbal substances. Compared to many other “testosterone boosters,” the study situation is much more solid here – but the effect remains moderate.
Most people tolerate Ashwagandha well. Occasionally, mild side effects such as stomach issues or fatigue occur. If there are pre-existing conditions, medical advice should be sought beforehand.
