Does ashwagandha cause diarrhea, nausea or an upset stomach?

Yes — loose stools, stomach discomfort, nausea and drowsiness are the most commonly reported ashwagandha side effects across human trials, and they're usually mild and temporary. A 2020 review of 30 human trials found these showed up in more than 5% of participants, with less common reports running the other direction, toward constipation instead.

What the side-effect data actually says

A 2020 systematic review pooled 30 human clinical trials of Withania somnifera (ashwagandha) root preparations and found no serious adverse events and no meaningful changes in bloodwork or vital signs across any of them. The most common adverse effects, reported in more than 5% of participants, were drowsiness, epigastric pain or discomfort, and loose stools. Less common effects — reported by a smaller share of participants — included nausea, decreased appetite, constipation, dry mouth, hyperacidity and skin rash. That review pooled trials using different forms and doses of ashwagandha root, not our exact 1,300 mg/day of root powder specifically, but it's the broadest side-effect picture we've found.

Diarrhea and constipation both show up

Interestingly, both loose stools and constipation appear in the same trial data — loose stools more often, constipation less so. That's consistent with individual variation in how people respond to a new supplement rather than one predictable direction. If you notice either, it doesn't mean something is wrong with the product; it's a reported range of responses, not a guaranteed one.

What's anecdotal, not measured

We haven't found a trial suggesting ashwagandha causes a sexual side effect of that kind. The one placebo-controlled trial that tested ashwagandha specifically in a diagnosed sexual-function condition found no significant difference between ashwagandha and a placebo over 60 days — a null result in either direction, not evidence of harm.

Nightmares, vivid dreams, emotional blunting, heartburn, dry mouth and heavy periods come up often in searches and forums, but no trial we've found has specifically measured any of these for ashwagandha. That's not the same as ruling them out — it means the data simply doesn't exist yet, and we're not going to claim confidence either way on something nobody has studied directly. If you're pregnant or trying to conceive, our label is direct regardless of these anecdotal reports: do not use if pregnant or nursing, and any pregnancy-related question, including miscarriage risk, is one to ask your doctor.

If you notice stomach upset

• Try taking it with food. Our label doesn't require food either way, but some people find it easier on the stomach with a meal.
• Give it a few days. The mild effects reported in trials were typically described as temporary.
• Persistent or severe symptoms are worth a doctor's attention, especially anything resembling the liver-injury warning signs — yellowing skin or eyes, dark urine, unusual itching, or pain under the right ribs. See is ashwagandha bad for your liver?.

Questions people ask

Does ashwagandha make you poop, or help with constipation?

Loose stools are one of the more commonly reported side effects in trials, but we don't claim ashwagandha relieves constipation — no trial we've reviewed tested it against constipation as an outcome, and some trial participants reported constipation as a side effect instead.

Can you take ashwagandha on an empty stomach?

Our label doesn't require taking it with food. If you're sensitive to supplements on an empty stomach, taking it with a meal is a reasonable personal adjustment rather than a label requirement.

Can ashwagandha cause nausea?

Nausea is listed among the less common adverse effects in the 2020 review of 30 human trials, alongside decreased appetite and dry mouth. It wasn't among the most frequently reported effects, but it has been reported.

Can ashwagandha cause heartburn or dry mouth?

Dry mouth is one of the less common adverse effects reported across the trials reviewed. We haven't found a trial specifically measuring heartburn as an outcome.

Related reading: how much ashwagandha is too much?, is it safe to take ashwagandha every day?, and ashwagandha side effects: the full list.