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Ashwagandha Side Effects: What the Research Actually Shows

LooksMaxxers Editorial January 22, 2026 8 min read

Ashwagandha Side Effects: What the Research Actually Shows

LooksMaxxers Editorial
January 2026 | 16 min read

Ashwagandha has exploded in popularity. It's promoted for everything from reducing stress and anxiety to boosting testosterone and improving sleep. But what does ashwagandha actually do? And what are the side effects you should know about?

This guide covers everything: what ashwagandha is, what the research shows it does, the documented side effects, differences between men and women, and whether it's worth taking.

What Is Ashwagandha?

Ashwagandha (Withania somnifera) is an herb that's been used in Ayurvedic medicine for thousands of years. It's classified as an "adaptogen" — a substance that helps the body adapt to stress.

The name comes from Sanskrit, roughly translating to "smell of horse," referring both to its distinct smell and the belief that it gives you the strength of a horse.

The active compounds in ashwagandha are called withanolides. Most research uses extracts standardized to contain specific percentages of these compounds (typically 2.5-5%).

Common forms include:

Capsules/tablets: Most convenient, standardized dosing
Powder: Traditional form, can be mixed into drinks
Gummies: Easier to take but often lower doses
Liquid extracts: Fast absorption

What Does Ashwagandha Do?

Ashwagandha has been studied for several effects. Here's what the research actually supports:

Reduces Cortisol and Stress

This is ashwagandha's most well-documented effect. Multiple studies show it significantly reduces cortisol levels — the body's primary stress hormone.

One study found ashwagandha reduced cortisol levels by 27.9% compared to placebo. Another showed reductions of up to 30% in chronically stressed adults.

Why this matters for looksmaxxing: Elevated cortisol promotes fat storage (especially facial bloating), breaks down muscle, disrupts sleep, and accelerates skin aging. Lowering chronically elevated cortisol can improve all of these.

Reduces Anxiety

Research consistently shows ashwagandha reduces anxiety symptoms. A systematic review of multiple studies found significant anxiety reduction compared to placebo.

It appears to work through multiple mechanisms including modulating GABA receptors and reducing cortisol.

Improves Sleep

Studies show ashwagandha can improve both sleep quality and the ability to fall asleep, particularly in people with insomnia or high stress. The effect is likely related to its cortisol-lowering and anxiety-reducing properties.

Taking ashwagandha before bed is common practice, though it can also be taken in the morning.

May Increase Testosterone

Several studies show ashwagandha can increase testosterone levels in men, particularly those who are stressed, have low testosterone, or are engaged in resistance training.

One study in men doing resistance training found a 15% greater increase in testosterone compared to placebo. Another in infertile men showed a 17% increase in testosterone levels.

The testosterone-boosting effect is likely partially mediated through cortisol reduction — high cortisol suppresses testosterone production.

May Improve Body Composition

Some studies show ashwagandha can increase muscle mass and strength, particularly when combined with resistance training. It may also help reduce body fat percentage.

One study found significantly greater increases in muscle strength and size in men taking ashwagandha versus placebo while following a resistance training program.

May Improve Cognitive Function

Research suggests ashwagandha may improve memory, reaction time, and cognitive task performance. Effects are more pronounced in people experiencing stress or cognitive decline.

Ashwagandha Side Effects

Ashwagandha is generally well-tolerated, but side effects do occur. Here's what you should know:

Common Side Effects

Gastrointestinal issues:

Stomach upset
Nausea
Diarrhea
Vomiting (rare)

These are the most commonly reported side effects, especially when starting or at higher doses. Taking ashwagandha with food typically reduces GI issues.

Drowsiness:

Due to its calming effects, ashwagandha can cause drowsiness in some people. This is why many take it before bed. If you experience drowsiness, avoid taking it before driving or activities requiring alertness.

Headache:

Some people report headaches, particularly when starting supplementation. This often resolves after the first week or two.

Less Common Side Effects

Thyroid changes:

Ashwagandha can increase thyroid hormone levels. This may be beneficial for those with underactive thyroid but problematic for those with overactive thyroid (hyperthyroidism) or thyroid conditions. If you have thyroid issues, consult a doctor before taking ashwagandha.

Changes in blood pressure:

Ashwagandha may lower blood pressure. This can be beneficial or problematic depending on your baseline. Those on blood pressure medications should be cautious.

Changes in blood sugar:

Some research shows ashwagandha can lower blood sugar levels. Diabetics or those on blood sugar medications should monitor levels carefully.

Allergic reactions:

Rare but possible. Those allergic to nightshades (tomatoes, peppers, eggplant) may be more likely to react to ashwagandha, which is in the same plant family.

Serious Side Effects (Rare)

Liver concerns:

There have been rare case reports of liver injury associated with ashwagandha supplements. While these are uncommon and causation isn't always clear, those with liver conditions should exercise caution and consult a doctor.

Drug interactions:

Ashwagandha may interact with:

Thyroid medications
Blood pressure medications
Diabetes medications
Immunosuppressants
Sedatives and anti-anxiety medications

If you take any medications, consult a healthcare provider before starting ashwagandha.

Ashwagandha Side Effects for Men

Men generally tolerate ashwagandha well. Specific considerations for men:

Testosterone increase:

While often desired, increased testosterone can theoretically have side effects in some individuals. In practice, the testosterone increases from ashwagandha are modest and unlikely to cause issues in healthy men.

Fertility effects:

Studies actually show ashwagandha may improve sperm quality and fertility in men — this is generally a positive effect, not a side effect. However, if you're concerned about any reproductive effects, consult a doctor.

Potential benefits for men:

Testosterone support
Improved body composition
Better stress management
Improved workout recovery

For men interested in looksmaxxing, the cortisol reduction and potential testosterone increase make ashwagandha particularly relevant.

Ashwagandha Side Effects for Women

Women should be aware of some specific considerations:

Hormonal effects:

Ashwagandha can affect hormone levels. While it doesn't significantly increase testosterone in women at normal doses, it does affect cortisol and may influence other hormones. Women with hormone-sensitive conditions should consult a doctor.

Pregnancy and breastfeeding:

Ashwagandha should NOT be taken during pregnancy. Some research suggests it may cause miscarriage. It's also not recommended while breastfeeding due to insufficient safety data.

Menstrual cycle:

Some women report changes to their menstrual cycle when taking ashwagandha. If you notice significant changes, discontinue use and consult a healthcare provider.

Thyroid considerations:

Women are more likely to have thyroid conditions. Since ashwagandha affects thyroid hormones, women with thyroid issues should be particularly cautious.

Potential benefits for women:

Stress and anxiety reduction
Improved sleep quality
Better cortisol management
Potential skin benefits through stress reduction

Ashwagandha and Testosterone

The ashwagandha-testosterone connection deserves special attention since it's a major reason people take it.

What the Research Shows

Multiple studies demonstrate ashwagandha can increase testosterone:

Resistance training study: 15% greater testosterone increase vs placebo over 8 weeks
Infertile men study: 17% increase in testosterone levels
Stressed men study: Significant increases in testosterone alongside cortisol reduction

How It Works

Ashwagandha likely increases testosterone through several mechanisms:

Cortisol reduction: High cortisol suppresses testosterone. By lowering cortisol, ashwagandha removes this suppression.
Antioxidant effects: May protect testosterone-producing cells from oxidative damage.
Direct effects: Some evidence suggests direct effects on testosterone production pathways.

Is It a "Testosterone Booster"?

Ashwagandha is one of the few natural supplements with actual evidence for increasing testosterone. However, keep expectations realistic:

Effects are modest (not comparable to TRT or steroids)
Works best in stressed individuals or those with suboptimal testosterone
Won't dramatically transform your physique on its own
Most effective when combined with resistance training, good sleep, and stress management

If your testosterone is already optimal and you're not stressed, you may see minimal effects.

Ashwagandha for Anxiety and Stress

This is ashwagandha's strongest and most well-documented use case.

The Evidence

Multiple high-quality studies show significant anxiety reduction:

One study showed a 69% reduction in anxiety and insomnia scores
A systematic review found consistent anxiety-reducing effects across multiple trials
Effects appear within 6-8 weeks in most studies

How It Works for Anxiety

Ashwagandha reduces anxiety through multiple pathways:

Cortisol reduction: Lower stress hormones = less physiological anxiety
GABA modulation: GABA is the brain's primary calming neurotransmitter
Serotonin effects: May influence serotonin pathways involved in mood

Ashwagandha vs. Anti-Anxiety Medications

Ashwagandha is not a replacement for prescribed anxiety medications. However, for mild to moderate stress and anxiety:

It has fewer side effects than most pharmaceuticals
It's not habit-forming (unlike benzodiazepines)
It can be used long-term
It addresses root causes (cortisol) rather than just symptoms

If you have diagnosed anxiety disorder, work with a healthcare provider rather than self-treating with supplements.

Ashwagandha Before Bed

Many people take ashwagandha before bed. Here's why:

Benefits of Nighttime Use

Improved sleep quality: Studies show better sleep when taken at night
Reduced time to fall asleep: The calming effects help with sleep onset
Morning cortisol regulation: May help normalize the cortisol awakening response
Drowsiness is a feature, not a bug: If it makes you sleepy, nighttime is ideal

Nighttime Dosing

For sleep benefits, take ashwagandha 30-60 minutes before bed. Start with a lower dose to assess how it affects you.

Some people prefer splitting doses — taking some in the morning for daytime stress relief and some at night for sleep.

Ashwagandha vs. Melatonin

Both can help with sleep, but they work differently:

Ashwagandha: Reduces stress/cortisol that interferes with sleep. Better for stress-related sleep issues.
Melatonin: Directly signals sleep timing. Better for circadian rhythm issues.

Some people use both together, though start with one to assess effects before combining.

Ashwagandha Benefits for Skin

Ashwagandha may benefit skin indirectly through several mechanisms:

Cortisol reduction:

Chronic stress and elevated cortisol accelerate skin aging, break down collagen, and can trigger acne and other skin issues. By reducing cortisol, ashwagandha may help prevent these stress-related skin problems.

Antioxidant effects:

Ashwagandha has antioxidant properties that may help protect skin from oxidative damage.

Improved sleep:

Better sleep quality means better skin repair and regeneration overnight.

Inflammation reduction:

Ashwagandha has anti-inflammatory properties that may benefit inflammatory skin conditions.

Don't expect dramatic skin transformation from ashwagandha alone — but as part of a comprehensive approach including proper skincare, sleep, and stress management, it can contribute.

Ashwagandha Dosage

Dosing depends on the form and extract type:

Standard Dosing

Root powder: 1,000-6,000mg per day
Standardized extract (2.5-5% withanolides): 250-600mg per day
KSM-66 extract: 300-600mg per day
Sensoril extract: 125-250mg per day

Dosing Tips

Start low: Begin with the lower end of the range to assess tolerance
Take with food: Reduces GI side effects
Be consistent: Effects build over weeks of consistent use
Cycle if desired: Some people take breaks (e.g., 8 weeks on, 2 weeks off) though this isn't strictly necessary

When to Take

For stress/anxiety: Morning or split doses
For sleep: 30-60 minutes before bed
For testosterone/gym: Timing is less critical; consistency matters more

Ashwagandha Gummies Side Effects

Gummies are a popular form, but have some specific considerations:

Lower doses:

Gummies often contain less ashwagandha than capsules or powder. Check the actual ashwagandha content, not just the serving size.

Added sugars:

Most gummies contain sugar or sweeteners. This adds calories and may not be ideal if you're watching sugar intake.

Same potential side effects:

GI issues, drowsiness, and other side effects can still occur with gummies.

May be easier to overuse:

Because they taste good, some people take more than recommended. Stick to the dosage on the label.

Who Should NOT Take Ashwagandha

Avoid ashwagandha if you:

Are pregnant or breastfeeding
Have hyperthyroidism or Graves' disease
Have autoimmune conditions (may stimulate immune system)
Are scheduled for surgery (stop 2 weeks before)
Have liver disease
Are allergic to nightshades

Use caution and consult a doctor if you:

Take thyroid medications
Take blood pressure medications
Take diabetes medications
Take sedatives or anti-anxiety medications
Have any chronic health conditions

Ashwagandha and Looksmaxxing: The Connection

Why is ashwagandha relevant to looksmaxxing? Several reasons:

Cortisol and facial bloating:

Chronic stress elevates cortisol, which promotes water retention and fat storage in the face. Reducing cortisol can help with a leaner facial appearance.

Sleep optimization:

Better sleep = better recovery, better skin, less under-eye circles, and improved overall appearance. Ashwagandha supports sleep quality.

Testosterone support (men):

Higher testosterone supports muscle development, fat distribution, and masculine features. Ashwagandha's testosterone support, while modest, contributes.

Stress management:

Chronic stress ages you. It affects your skin, your face, your body composition, and your energy. Managing stress is foundational to looking your best.

Workout recovery:

For gymmaxxing, ashwagandha may improve recovery and support muscle growth, particularly when combined with resistance training.

The Bottom Line

Ashwagandha is one of the most well-researched herbal supplements with legitimate evidence for:

Reducing cortisol and stress
Decreasing anxiety
Improving sleep
Modestly increasing testosterone (in men)
Potentially improving body composition

Common side effects include GI upset, drowsiness, and headache — usually mild and often resolved by taking with food or adjusting dose.

Serious concerns are rare but include thyroid effects, potential liver issues (rare), and drug interactions.

Who it's best for:

People dealing with chronic stress
Those with anxiety (mild to moderate)
Men looking to support testosterone naturally
Anyone with stress-related sleep issues
Looksmaxxers wanting to optimize cortisol and recovery

Who should skip it:

Pregnant or breastfeeding women
Those with thyroid conditions (without doctor approval)
People on medications that may interact
Anyone with liver concerns

If you're generally healthy, stressed, and looking to optimize your hormones and recovery, ashwagandha is worth considering. Start with a low dose, take it consistently for at least 4-6 weeks, and assess how you respond.

It's not a magic pill, but it's one of the few supplements with actual evidence behind it.

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