Top News

Magnesium may be all you need, but these three supplements could offer extra sleep support.

Reviewed by Dietitian Katey Davidson, M.Sc.FN, RD, CPT

Key Points

• Magnesium alone may be enough to support better sleep for many people.
• L-theanine, melatonin and ashwagandha show promise, but more research is needed.
• Healthy sleep habits remain the foundation of better sleep.

Magnesium has earned its reputation as one of the go-to supplements for better sleep. It plays a role in hundreds of processes in your body, including the systems that help you relax and wind down at night. For people looking to optimize sleep, it’s often one of the first supplements recommended. But questions remain about whether pairing it with other supplements might offer additional benefits.

Is magnesium best on its own, or does pairing it with something else make a difference? We spoke with two registered dietitians to sort through what the research actually shows. Below, you’ll find three supplements that may work well alongside magnesium for sleep support, along with some important caveats, plus a look at why magnesium on its own might be all you need.

1. L-Theanine

L-theanine is an amino acid found naturally in tea leaves. It’s often studied for its calming effects, and some research suggests it may help you feel more relaxed without making you drowsy during the day.

A few small studies have looked at L-theanine and sleep quality. Some findings suggest it may help people fall asleep more easily and feel more rested, possibly by promoting relaxation and lowering stress rather than directly inducing sleep. That said, the research is still limited, and many studies use small sample sizes or combine L-theanine with other ingredients, making it difficult to isolate its effects.

“L-theanine is interesting because it seems to promote a calm, settled feeling that can make it easier to wind down at night,” shares Jamie Lee McIntyre, M.S., RDN. “Paired with magnesium, which also supports relaxation, it may be a reasonable combination to try, though I’d stress that the current evidence is early and not definitive.”

If you want to experiment with L-theanine, it’s worth talking with your health care provider first, especially if you take other medications or supplements.

2. Melatonin

Melatonin is a hormone your body produces naturally, and its levels increase as nighttime approaches. It helps regulate your sleep-wake cycle, signaling to your body that it’s time to sleep.

Studies suggest melatonin may help you fall asleep a little faster and can be especially useful if your sleep schedule is disrupted, such as from jet lag or shift work. It’s generally considered most helpful for timing- sleep issues rather than as a nightly sleep aid.

“Melatonin can be helpful, but it’s not a sedative and shouldn’t be treated like one. The evidence is strongest for resetting a disrupted sleep schedule,” says McIntyre. “If someone is already using magnesium and adds a low dose of melatonin for a short period, that may be a sensible, evidence-informed approach, but it’s not meant for indefinite nightly use without guidance.”

Because melatonin can affect people differently, it’s smart to start with the lowest dose and check in with your provider, particularly if you’re pregnant, breastfeeding or taking other medications.

3. Ashwagandha

Ashwagandha is an herb used in traditional medicine, often described as an adaptogen, which is a substance thought to help the body adapt to stress. Since stress and poor sleep frequently go hand in hand, researchers have explored whether ashwagandha might support better rest.

Some small studies suggest ashwagandha may improve sleep quality and help people feel less stressed, which could indirectly support sleep. A few reviews have found modest benefits, but experts agree the research is still emerging. Study designs vary widely, and long-term safety data is limited.

“Ashwagandha shows some promise, particularly for people whose sleep is affected by stress. But I always remind clients that the studies are small and short-term,” shares Toby Amidor, M.S., RDN, CDN. “It may complement magnesium for someone dealing with stress- sleep trouble, yet we shouldn’t overstate what it can do.”

If you’re considering ashwagandha, keep in mind it isn’t right for everyone. Ashwagandha may interact with certain medications and is not recommended during pregnancy, breastfeeding or for people with certain health conditions. Speak with your health care provider first before adding ashwagandha to your routine.

Is Magnesium on Its Own OK?

For many people, magnesium alone is a solid starting point for supporting sleep. It’s better studied compared to some other options, and it plays a genuine role in the body’s relaxation processes. Some research suggests magnesium may help improve sleep quality, particularly in people who have lower magnesium levels, though findings are mixed and more high-quality studies are needed.

Before you start stacking supplements, it’s worth giving magnesium a fair trial on its own. That way, you can see how your body responds without adding variables that make it harder to know what’s actually working.

“Magnesium by itself is a reasonable, evidence-supported place to begin,” says Amidor. “I’d rather someone see how magnesium works for them first, then consider adding one other supplement thoughtfully, rather than taking several at once and hoping something helps.”

It’s also worth remembering that supplements work best alongside good sleep habits. Keeping a consistent bedtime, limiting screen time before bed and creating a calm sleep environment can make a meaningful difference.

Our Expert Take

Magnesium is a well-regarded option for supporting sleep, and for many people it works well on its own. If you want to try pairing it with something else, L-theanine, melatonin and ashwagandha each have some research behind them. However, the evidence is still limited, and none should be treated as a guaranteed fix.

The most sensible approach is to start with magnesium alone, give it time and then add just one supplement if you feel you need more support. Always talk with your health care provider before starting anything new, especially if you take medications or have underlying health conditions. Pair your supplement routine with healthy sleep habits, and you’ll give yourself the best chance at better rest.