With fewer Americans getting the recommended eight hours of sleep and more of them saying they need more sleep, per an April 2024 Gallup poll, I’m just one of many helping the sleep aids market grow to $130 billion. Part of that market involves sleep supplements like melatonin, as well as the herbal based ashwagandha. While I pull out the former when I fear an oncoming insomnia onslaught, I know several people who have been taking melatonin nightly for years (unfortunately for them, this probably isn’t a great idea). And a friend of mine swears by the anxiety and stress-relieving benefits of ashwagandha that help her fall into a quick slumber.

But when stacked up against one another, which one should we actually be taking to help us sleep—and should we even be taking them at all?

What are melatonin and ashwagandha?

Melatonin is a naturally occurring hormone produced in the brain’s pineal gland that regulates our circadian rhythm. By acting as our body’s internal clock, it helps us know when to go to bed (thanks to higher levels at night) and when to wake up (thanks to lower levels in the morning). We can add more melatonin to our system in the hopes of promoting sleep through natural or synthetic versions of it in tablets, gummies, and the like.

Ashwagandha is an adaptogen, an herb that helps regulate the stress hormone cortisol. It comes from a shrub that grows in Africa and Asia, but you can often buy it as a capsule, powder, or tea. Research shows it can improve brain function and lower inflammation, plus help reduce stress and anxiety—which can make for a good night’s sleep.

Is melatonin or ashwagandha more effective for sleep?

The research is mixed on just how well melatonin and ashwagandha supplements can knock us out at night. A January 2022 study published in the National Library of Medicine finds that melatonin positively affects our quality of sleep. But a study published the same year in Journal of the American Medical Association (JAMA) finds “weak” evidence in melatonin use for sleep disturbances. 

As for ashwagandha, various studies find that it has a small, but significant effect in improving sleep, particularly when taken eight weeks in a row and by those suffering from insomnia.

When deciding between the two, “the key is to note if the key problem is just falling asleep or also staying asleep,” says Dr. Jacob Teitelbaum, who specializes in treating conditions such as chronic fatigue syndrome, fibromyalgia, and long COVID and who wrote From Fatigued to Fantastic, which addresses sleep disorders.

For those who have trouble falling asleep, he tells Fortune, he typically recommends starting with 5 mg of one of the best melatonin supplements. For those who wake up in the middle of the night, he recommends a sustained release of a higher dose of melatonin. To reap the sleep benefits of ashwagandha, he says the supplement must be at least 5% potency, good quality, and a 600 mg dose. He adds that both can go well together.

When insomnia is the key issue, he typically begins with a sustained-release of 10 mg of melatonin, adding other treatments as needed. If severe daytime fatigue is present, then he adds high potency ashwagandha to help both energy and insomnia.

“Melatonin is most effective for helping sleep, but also helps with nighttime acid reflux, along with antioxidant, immune, and neuroprotective benefits,” he says. “Ashwagandha helps sleep as one of its modest components, but does also help energy, cognition, stress, and other functions. Both melatonin and ashwagandha improve sleep as well as energy.”

Is melatonin or ashwagandha safer for sleep?

Since sleep medications can cause significant problems, Teitelbaum likes to start with natural, safer alternatives like melatonin and ashwagandha. While one isn’t necessarily “safer” than the other, you should make sure they’re certified by NSF International, which verifies the purity of supplement ingredients. And, as with most things in life, they should be taken in moderation because there are risks to taking too much.

Although ashwagandha is safe for adults, according to the NIH, its side effects can show up as diarrhea, drowsiness, a headache, and upset stomach. Melatonin can also cause nausea, dizziness, drowsiness, and a headache, per the Cleveland Clinic. You shouldn’t take either if you’re pregnant or breastfeeding. While using them in the short-term is okay, little is known about using them long-term—although we can become psychologically dependent on melatonin, since some experts believe its effectiveness lies in a placebo effect.

Teitelbaum says it’s reasonable to use either intermittently during periods of stress or insomnia, or even indefinitely. But there’s little known about the effects of long-term melatonin use, so it’s best to run your specific sleeping problems by a specialist who can help you figure out a nighttime game plan. Many experts agree it’s important to not rely on either supplement as a cure-all for your sleep problems. 

Dr. Jennifer Martin, a psychologist and immediate past president of the American Academy of Sleep Medicine, previously told Fortune she doesn’t recommend supplements for sleep at all—rather, you should focus on boosting your sleep hygiene. And Dr. Ana Kreiger, medical director of the Center for Sleep Medicine at Weill Cornell Medicine and NewYork-Presbyterian, explained to Fortune that supplements are best used in conjunction with enhancing your nighttime routine.

That looks like a dark and cool bedroom, a routine with a regular bedtime and wake-up time, limiting light exposure before bed, and learning “how to reduce stressors and underlying anxieties that may be affecting sleep,” Kreiger said.

As with any change to our health routine, it’s always important to talk to your doctor first to determine the best way to tackle your sleep problems and which supplement might be right for you, if at all.

More on sleep:

• You’re probably taking too much melatonin—and using it too often
• Watch out for these 8 ways you may be sabotaging your sleep
• How late in the day can you drink coffee? What time you can have your last cup and still fall asleep at night
• Can’t get a good night’s rest? 8 ways you may be sabotaging your sleep