Ashwagandha is having a moment.

If you haven’t heard of it, you’re probably not among TikTok’s 1.6 billion active users.

And as is the case with most viral trends, the hype can be embraced — or discounted — depending on who you are. Millions extol the benefits of the herb that’s been shown to relieve stress and anxiety and promote sleep, much like ginseng.

And although its effectiveness has been proven in a number of clinical studies, some studies have identified adverse effects that are a major concern for others.

“Liver toxicity is the biggest concern,” said Dr. Stewart Trimble, an internal medicine doctor with Novant Health Sewee Family Medicine in Mount Pleasant, South Carolina. “So, a patient who has anything wrong with the liver — alcohol overuse, fatty liver, cirrhosis, etc. — should avoid ashwagandha.”

It’s a good news/bad news kind of thing with ashwagandha, which comes in capsule form. Many people have used it safely and find it highly effective. But others should ignore the hoopla. No matter which camp you’re in, always talk with your doctor or other clinician before taking any supplement (even natural ones) or vitamin.

Trimble helped sort out the good and the bad of the latest wellness craze. (And by the way, it’s pronounced: ash-wa-GON-da.)

The good

What conditions does ashwagandha treat?

Clinical studies show that four main groups of people benefit from taking ashwagandha. They are people age 16 and up with:

• Diagnosed insomnia. If you merely have poor sleep hygiene (meaning you don’t have habits and an environment that help you get good, restful sleep on a regular basis), ashwagandha won’t be as effective for you.
• Chronically elevated stress levels. What makes stress “chronic” isn’t just how intense it is, but how persistent and unrelieved it becomes. Chronic stress means your body is not returning to a calm state between stressful episodes.
• Mild to moderate anxiety or depression. Ashwagandha is intended as a complementary approach to, and not a substitute for, more conventional treatment, including counseling and possibly medication. For mild anxiety or depression, exercise can be an effective first line of defense.
• Stress-related cognitive impairment. In everyday terms, that can mean stress is affecting your ability to concentrate or think clearly. Mental fatigue and “brain fog” are common examples.

Ashwagandha for sleep: Ashwagandha can help significantly in speeding up sleep onset, sleep efficiency (getting into the restorative sleep phases), total sleep time and in falling back asleep after waking up in the middle of the night.

Ashwagandha for anxiety or stress: Ashwagandha has been shown to improve executive functioning, recall memory, pattern recognition, multitasking ability and concentration/decision-making speed in adults with cognitive impairment related to chronic stress or anxiety.

People hoping to calm their nerves before a particular anxiety-inducing event aren’t likely to get much benefit from the herbal remedy.

Because depression and anxiety are two sides of the same coin, ashwagandha generally has the same benefits for depression as it does for anxiety.

What’s the right dose for ashwagandha? And how long do you take it?

Studies show that patients get the most benefit from taking 300 to 600 mg once per day for a minimum of eight weeks. Optimal benefits occur between eight and 12 weeks.

That’s not to say it stops working after 12 weeks. “But — and this is true of any drug — your body may stop responding to it after that point,” Trimble said. “That’s called tachyphylaxis, and it’s an acute decrease in response to a drug after repeated doses, resulting in a loss of efficacy.”

Twelve weeks is also the point at which it could begin doing harm to people with liver or thyroid issues. “It’s important to have your liver enzymes checked after about 12 weeks,” Trimble said. “If all is well and it’s been working for you, you can keep taking it.”

Trials have studied ashwagandha use for up to 90 days, in which it’s been shown to be safe and effective for the populations studied. More studies are needed on longer-term use.

Ashwagandha dose for sleep: How soon it should be taken before bedtime can vary dramatically from one person to the next. “I recommend taking it the first night at about sunset,” Trimble said. “Notice how long it takes before it’s effective and how you rested you feel the next morning. It may involve some trial and error before you know your own ideal time to take it. Be aware that taking it on a full stomach means it will take longer to work.”

Ashwagandha dose for anxiety or stress: It can be taken any time of day. It’s designed to be taken regularly so that you benefit from the cumulative effect of daily dosing. Most clinical trials use 240 to 600 mg a day, but benefits have been shown at up to 1,200 mg per day.

Studies have also shown some patients have reduced morning cortisol levels. That’s the clinical name for the stress hormone, which surges in the morning.

“For people with sleep disorders, that morning cortisol spike can be too much,” Trimble said. “A potential benefit of ashwagandha is that it may blunt morning cortisol.”

The bad

Risks, drug interactions and side effects of ashwagandha

Ashwagandha is generally safe for most people, but there are some important caveats related to:

• Liver disease. “The most dangerous thing about ashwagandha is its potential effect on the liver,” Trimble said. “If you have a healthy liver and you’re not a heavy drinker, you’re unlikely to experience any issues. But if there’s any doubt, you shouldn’t take it.” If you’re taking a hepatotoxic medication (one that can do liver damage), including antibiotics and acetaminophen, you should avoid ashwagandha, Trimble said.
• Thyroid disorders. “It can have some effect on the thyroid, too,” Trimble said. “So, if you’re on thyroid medication (or are prone to hyperthyroidism, which is when the metabolism is turned up too high), on liver medication or taking any medication that can interfere with the liver — certain toenail fungus medications, for example — you should avoid it.”

• Certain drugs may be dangerous to take with ashwagandha. They include (but aren’t limited to) tacrolimus, levothyroxine, propofol, ketamine, cyclosporine, cyclophosphamide, Wellbutrin, methadone and Sustiva. If you’re on any of these, do not mix them with ashwagandha.
• Some online forums claim that ashwagandha may interfere with oral contraceptives. Trimble said that appears to be a myth unless you take ashwagandha at a very high dose, which he doesn’t recommend under any circumstances.

Mild side effects of ashwagandha

The most common ones reported are:

• Drowsiness
• Burning, aching or cramping in the upper abdomen
• Loose stools

Odor

You may be wondering about the origin of the name ashwagandha. And that brings us to a final potential, although unlikely, negative.

The tongue twister of a name comes from the Sanskrit words ashva (horse) and gandha (smell). The root from which ashwagandha is derived has a strong, horse-like odor. By the time it’s in capsule form, it shouldn’t have any odor. But if you’re highly sensitive to smells, you may detect something.

Bottom line

“Ashwagandha is a great thing to consider for the conditions it’s been shown to alleviate,” Trimble said. “But you should always talk to your doctor before trying any new supplement. Ask your doctor first if there are any concerns about liver or thyroid problems.”

“The ideal patient is someone struggling with a temporary, stressful event and whose stress is causing them anxiety or trouble sleeping,” he added.

“The last thing I’ll note is that ashwagandha, like all herbal supplements, isn’t regulated by the FDA. So, it’s important to buy it from a reputable source. There’s a subscription website ($69/year) called consumerlab.com that can help you determine which brands are worth the money,” he said. “Consumer Lab tests samples from a dozen or more manufacturers — not for efficacy, but to ensure the capsule has all the ingredients it claims to have.”