Does Ashwagandha Cause Weight Gain? What Studies Actually Show

Last reviewed: April 18, 2026 · Reviewed by the YourHealthier Science Team · Editorial Policy

If you've searched "does ashwagandha cause weight gain," you're probably seeing mixed signals — some people on Reddit say they gained weight, others say they lost it, and most articles give you a vague "it depends." Here's what the clinical research actually shows.

Short answer: No. There is no clinical evidence that ashwagandha causes fat gain. One well-designed study found the opposite — ashwagandha reduced body weight and BMI in adults under chronic stress (Choudhary et al., 2017, PubMed). The only scenario where ashwagandha might contribute to weight gain is through increased muscle mass during resistance training, which is a fundamentally different kind of weight change.

What the research says about ashwagandha and body weight

The key study: Choudhary et al., 2017

This is the most directly relevant trial. Published in the Journal of Evidence-Based Complementary & Alternative Medicine, it was a double-blind, randomized, placebo-controlled study of 52 adults under chronic stress.

Participants took either 300 mg of ashwagandha root extract twice daily (600 mg total) or placebo for 8 weeks. The ashwagandha group showed:

• Statistically significant reduction in body weight compared to placebo
• Statistically significant reduction in BMI compared to placebo
• Significant reduction in serum cortisol levels (the stress hormone)
• Significant reduction in food cravings and improvement in eating behaviors

The researchers concluded that ashwagandha may support body weight management in people experiencing chronic stress — and the mechanism appeared to be through cortisol reduction, which reduced the stress-driven eating and fat storage patterns that lead to weight gain (Choudhary et al., 2017, PubMed).

This isn't saying ashwagandha is a weight loss supplement. It's saying that for people whose weight gain is partly driven by chronic stress and elevated cortisol, ashwagandha may help by addressing the hormonal root cause.

Ashwagandha and muscle mass

A 2015 study published in the Journal of the International Society of Sports Nutrition found that men who took 300 mg of ashwagandha root extract twice daily while performing resistance training for 8 weeks gained significantly more muscle mass and strength than the placebo group (Wankhede et al., 2015, PubMed).

This is where the "ashwagandha causes weight gain" confusion likely originates. If you're strength training and taking ashwagandha, you may see the number on the scale go up — but that's lean muscle mass, not fat. Your body composition is actually improving. Body fat percentage in the ashwagandha group was also reduced compared to placebo.

What WebMD and GoodRx say

WebMD's assessment: weight gain is not a commonly reported side effect of ashwagandha, and the herb has not been specifically studied as a tool for gaining or losing weight — though one study found it may reduce food cravings in chronically stressed adults (WebMD, 2024).

GoodRx's clinical review reached a similar conclusion: ashwagandha is unlikely to cause weight gain, and there's some preliminary evidence it could help with weight loss, though the research is limited and indirect (GoodRx, 2025).

Why people think ashwagandha causes weight gain

The confusion comes from a few sources:

1. Cortisol and appetite changes. Ashwagandha lowers cortisol. In some people, chronically elevated cortisol actually suppresses appetite (the "too stressed to eat" pattern). When cortisol normalizes, appetite may return to baseline — which can feel like increased hunger. This isn't ashwagandha causing weight gain; it's your body returning to normal appetite regulation.

2. Thyroid hormone effects. Some studies suggest ashwagandha may mildly increase thyroid hormone levels, particularly T4. Thyroid hormones influence metabolism, and the relationship between thyroid function and weight is complex. In people with subclinical hypothyroidism, a slight thyroid boost could theoretically increase appetite and energy — but neither study proves a direct link to weight gain. If you have thyroid conditions, discuss ashwagandha with your doctor.

3. Improved sleep → recovery → muscle. Ashwagandha's sleep-improving and cortisol-lowering effects mean better recovery. Better recovery combined with any physical activity can support lean mass development. Again — lean mass, not fat.

4. Individual variation and confounders. Supplement use rarely exists in isolation. People start ashwagandha during lifestyle changes, seasonal shifts, or alongside other supplements. Attributing weight changes solely to ashwagandha without controlling for diet and activity is unreliable — which is why controlled studies (like Choudhary 2017) are more informative than Reddit anecdotes.

The cortisol-weight connection: why it matters

This is worth understanding because it explains most of ashwagandha's relationship with body weight.

Chronic psychological stress elevates cortisol. Sustained high cortisol triggers a cascade that promotes weight gain:

• Increased visceral fat storage (particularly around the abdomen)
• Heightened food cravings — especially for sugar and refined carbohydrates
• Reduced insulin sensitivity (making it easier to store fat and harder to burn it)
• Disrupted sleep, which further compounds metabolic dysfunction

A 2012 study (Chandrasekhar et al., PubMed) found that 300 mg of ashwagandha root extract twice daily significantly reduced serum cortisol levels compared to placebo. Multiple subsequent studies have confirmed this cortisol-reducing effect.

By lowering cortisol, ashwagandha doesn't directly burn fat — but it removes one of the key hormonal drivers that makes stress-related weight gain happen in the first place. Think of it as removing a barrier rather than adding a solution.

For more on how ashwagandha manages stress and cortisol: Ashwagandha Benefits and KSM-66 vs. Regular Ashwagandha Extract.

What ashwagandha won't do for weight

To be clear about what's not supported by evidence:

• Ashwagandha is not a weight loss supplement. Don't expect it to replace caloric deficit or exercise.
• Ashwagandha does not directly increase metabolic rate in any clinically meaningful way.
• Ashwagandha does not "burn fat" — that framing is marketing language with no research backing.
• If your weight gain is driven by caloric surplus, medical conditions (like PCOS or hypothyroidism), or medication side effects, ashwagandha alone won't reverse it.

What ashwagandha can do is address the stress-cortisol-weight axis — one piece of a larger puzzle. It works best alongside sleep optimization, dietary improvement, and physical activity.

Our product: Ashwagandha Plus (KSM-66)

Our Ashwagandha Plus uses KSM-66 ashwagandha root extract — the most clinically studied ashwagandha extract on the market. KSM-66 is what was used in the Choudhary 2017 weight management trial and the Chandrasekhar 2012 cortisol reduction trial. It's standardized to a minimum 5% withanolides using a root-only extraction process.

• Ashwagandha root extract (KSM-66): 600 mg per serving
• Black pepper extract (BioPerine): 10 mg (enhances absorption)
• Serving size: 2 capsules
• Supply: 60 capsules (30-day supply)

Third-party tested for purity and potency by an independent ISO 17025-accredited laboratory. COAs available at Lab Results.

How to take ashwagandha if you're concerned about weight

Dose: 600 mg per day (300 mg twice daily), which matches the protocol in the Choudhary weight management study.

Timing: Split between morning and evening, or take the full dose in the evening if your primary goal is sleep and cortisol support. For detailed timing guidance: Best Time to Take Ashwagandha.

Duration: Most studies showing body composition benefits run 8–12 weeks. Give it at least 4 weeks before evaluating effects.

Complementary stack: Ashwagandha pairs well with Berberine HCl for metabolic health (berberine supports blood sugar and insulin sensitivity from the AMPK pathway, while ashwagandha addresses cortisol) and Magnesium Glycinate for sleep quality. See: Best Time to Take Berberine and Magnesium Glycinate for Sleep.

Frequently Asked Questions

Does ashwagandha cause belly fat?

No. Research suggests the opposite — ashwagandha reduces cortisol, which is the hormone most associated with visceral (belly) fat accumulation. The Choudhary 2017 RCT found reduced body weight and BMI in the ashwagandha group compared to placebo.

Does ashwagandha increase appetite?

It depends on your starting point. If chronically elevated cortisol has been suppressing your appetite, normalizing cortisol with ashwagandha may restore normal hunger signals. This isn't ashwagandha increasing appetite beyond normal — it's your body returning to baseline. In the Choudhary study, ashwagandha actually reduced food cravings.

Does ashwagandha make you gain muscle?

It can support muscle growth when combined with resistance training. The Wankhede 2015 study found greater gains in muscle mass and strength compared to placebo. This may show as increased scale weight, but body composition is improving — you're gaining lean mass and losing fat.

Should I stop taking ashwagandha if I'm gaining weight?

First, determine the type of weight gain. If you're strength training and gaining muscle, that's a positive outcome. If you're gaining fat, the cause is likely dietary or lifestyle-related rather than ashwagandha. No clinical evidence links ashwagandha to fat gain. If you're concerned, track body measurements (waist, hips) rather than scale weight alone.

Is ashwagandha safe for weight loss?

Ashwagandha is not a weight loss supplement and shouldn't be used as one. However, for people whose weight gain is stress-related, addressing cortisol with ashwagandha (alongside diet and exercise) may help remove a hormonal barrier to weight management.

How long does ashwagandha take to affect weight?

The Choudhary study measured significant differences at 8 weeks. Most clinical effects of ashwagandha (stress reduction, cortisol lowering, sleep improvement) begin to appear within 4–6 weeks of consistent daily use.

Related Reading

• Ashwagandha Benefits: What It Does and How to Take It
• KSM-66 vs. Regular Ashwagandha Extract
• Ashwagandha for Sleep and Anxiety
• Best Time to Take Ashwagandha
• Berberine Benefits: What It Does for Blood Sugar, Metabolism, and More
• Magnesium Glycinate for Sleep: What 2025–2026 Research Shows

References

1. Choudhary D, Bhattacharyya S, Joshi K. Body weight management in adults under chronic stress through treatment with ashwagandha root extract: a double-blind, randomized, placebo-controlled trial. Journal of Evidence-Based Complementary & Alternative Medicine. 2017;22(1):96-106.
2. Wankhede S, Langade D, Joshi K, Sinha SR, Bhattacharyya S. Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. Journal of the International Society of Sports Nutrition. 2015;12:43.
3. Chandrasekhar K, Kapoor J, Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian Journal of Psychological Medicine. 2012;34(3):255-262.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Always consult your healthcare provider before starting any new supplement.