Do any over-the-counter sleep remedies work?

Antihistamines

Sedating antihistamines, such as diphenhydramine, can be bought over the counter from pharmacies.  

These medicines come with risks such as daytime sleepiness, grogginess and falls. They can also affect activities such as driving, because they can cause you to still feel drowsy the next morning.  

The research says:

Antihistamines aren’t recommended for insomnia because they don’t treat the cause of your sleeping problems.

A 2015 review of randomised controlled studies over 12 years found diphenhydramine lacked robust clinical evidence to support its efficacy and safety as a sleep aid. 

In 2017, the American Academy of Sleep Medicine advised against treating chronic insomnia with common over-the-counter antihistamines. There wasn’t enough evidence they’re effective or safe.  

In 2019, the Royal Australian College of General Practitioners said antihistamines aren’t recommended due to little evidence that supports their use. 

Dr Bronwyn Sweeney – clinical psychologist and Honorary Research Associate at Massey University – said there are big cautions and caveats that go with using over-the-counter sleep aids, such as antihistamines.  

“It is really important people consult either with their doctor or the pharmacist about using these remedies, especially the antihistamines. They can interact with other medications and remedies being taken. This is especially so for older adults who tend to have other health challenges going on and may be taking other medications,” Dr Sweeney said.  

“The timing is also important. Sometimes people take these remedies during the night after lying awake for ages. This means the substance is still active come morning.”  

Magnesium

Pharmacies and supplement stores sell the naturally occurring mineral magnesium as a sleep aid. We found supplements containing magnesium that claim to “support switching off and staying asleep” and “support healthy sleep patterns”. One product advertised a “powerful formula to support deep restorative sleep”. 

The research says:  

A 2021 BMC Complementary Medicine and Therapies review of the effects of magnesium for insomnia in older adults confirmed the quality of studies was “substandard” for physicians to recommend magnesium.  

Otago University WellSleep Centre Associate Professor Angela Campbell said magnesium has poor quality of evidence to help with sleep. 

“A number of studies have been done in older adults but, overall, there were no significant differences in sleep measures. While there is anecdotal evidence that it helps with restless legs, the scientific evidence is lacking,” she said.  

B vitamins 

We found supplements containing vitamins B3, B5, B6 and B12 with claims such as “support for deep restorative sleep”.

The research says:

Dr Campbell said there’s not a lot of research that has been completed looking just at Vitamin B in a robust scientific manner. 

Valerian and hops 

Valerian or valerian root is a plant derivative that’s long been used to aid sleep. We found supplements in capsule and liquid supplement form touting claims that valerian supports restful sleep. It’s also sold as a tea.  

The research says:

In 2015, a Primary Care Companion for CNS Disorders review included 12 placebo-controlled randomised studies that investigated valerian or a combination of valerian and hops. It found limited evidence valerian could help with occasional bad sleep and insomnia. 

A separate 2015 Pharmacy & Therapeutics review found that, overall, the evidence for valerian as an insomnia treatment remains inconclusive. It’s also not recommended by the US Food and Drug Administration as a sleep aid. 

Tart cherry  

We found products advertising the sleep benefits of tart cherry or tart cherry extract. One product containing tart cherry claimed: “This synergistic blend offers the ultimate combination to help calm the body, unwind, relax a busy mind, and support a restful sleep.” 

The research says:

A 2010 study in the Journal of Medicinal Food found tart cherry juice may modestly improve sleep in older adults with insomnia. However, the study had a small sample size of 15 people and a short treatment period of two weeks.  

The study also noted that the effects were considerably less than those for evidence-based treatments for insomnia, such as cognitive behavioural therapy. It concluded further study of the sleep-promoting effects of tart cherries was needed.   

Tart cherry can have low levels of melatonin, which has been linked to improved sleep. However, Dr Sweeney said “the claims [of tart cherry products] are around its melatonin content, but the amounts are usually so low as to not have a therapeutic effect”. 

Sleep tips

• Don’t get attached to perfect sleep. It’s normal to occasionally have a bad sleep.

• Cognitive behavioural therapy works. The Australasian Sleep Association, American Academy of Sleep Medicine, American College of Physicians and European Sleep Research Society all recommend cognitive behavioural therapy for insomnia as the first line of treatment. It usually involves a comprehensive sleep assessment and then a personalised plan of treatment over a couple of months.

• Have a regular wake time. It helps set the body’s internal clock, which helps drive sleep.

• Relax before bed. Have a wind-down period of 30-60 minutes with softer lighting and no work, cellphones or laptops.

• Avoid caffeine and alcohol before bed. Learn techniques to wind down instead.

• Exercise and taking breaks during the day can help you nod off later one.

• Talk to your GP if you’re having trouble sleeping. They can check for physical factors that could impact sleep, such as sleep apnoea, poor thyroid function or low iron levels.

Regulation problems

It’s hard to know what’s exactly in sleep supplements, as manufacturers aren’t required to get approval before putting their products on the market.  

A product must provide the nutrients or dose listed on the label. Otherwise, it’s breaking the law and the company could be hit with a fine of up to $600,000.  

However, the only way to tell if a pill contains what it says it does is via expensive testing. 

There’s also no pre-vetting of claims. Dietary supplements can’t claim to treat or prevent a condition, but suppliers get around this by using vague language such as “supports a restful sleep”.  

We think companies should regularly review the science to ensure their products don’t put customers at risk of bad side effects.