Q: I’ve seen many new supplement pills and beverage “shots” that claim to help promote sleep. Do they work and are they safe?
A: Currently available sleep supplements contain a very broad range of ingredients, but common ones include amino acids (protein building blocks) such as L-tryptophan, L-theanine and 5-HTP, a hormone called melatonin, and various herbal extracts like chamomile, valerian, passion flower or lemon balm. Many products do not list the active ingredient doses in their products, and since supplements are not regulated by the FDA, even products that do list doses may or may not actually contain what the label says they do. All of these factors make it very difficult to evaluate whether sleep supplements in general are likely to be effective.
These caveats aside, what does the science say about these supposedly sleep-promoting ingredients? As you can see below, not a whole lot:
- L-tryptophan: There is a small amount of older research from the 1960s through the early 1980s which suggests that tryptophan taken before bed can help decrease the amount of time it takes to fall asleep in people with mild insomnia. It does not appear to benefit severe insomniacs or people with mental illness, nor has it been well-proven to extend the duration of sleep. The effective dose in the limited available research is about 1 gram, but there are some safety concerns (see below).
- L-theanine: There is virtually no data in human subjects that investigates whether L-theanine, a compound found naturally in tea, helps promote sleep. In fact, the limited available human research suggests that at doses of 50-100mg, L-theanine promotes mental alertness/focus without inducing drowsiness.
- 5-HTP: This amino acid is made by our bodies from tryptophan as an intermediate step toward making the neurotransmitter (brain signalling chemical) serotonin. Typically, it’s been used to treat depression, so almost no evidence exists regarding its effect on sleep. A super-small recent study (18 subjects) which compared the use of a supplement containing both 5-HTP and another amino acid called GABA to placebo did suggest a benefit in both time to fall asleep as well as duration of sleep. However, the authors did not report the dose of 5-HTP contained in the supplement, nor is it clear which compound may have been responsible for the observed benefit.
- Melatonin: Also made in our bodies from tryptophan, natural melatonin plays a role in our body’s normal sleep cycle (the so-called “circadian rhythms”). A fair amount of good evidence does suggest a limited role for it in helping sleep disturbances, especially those caused by a disrupted natural sleep-wake cycle (such as jet lag or disturbed weekend sleep patterns). It may be less helpful if the cause of your insomnia is related to something else. Effective doses appear to be 2 to 5mg taken before bed.
- Herbal ingredients: The most promising herbal ingredient appears to be Valerian root extract, for which there is some very limited evidence suggesting it may help people with mild insomnia fall asleep faster. Still, the research is contradictory and it’s unclear whether the benefit is only seen with use over several weeks or if it can be effective as an occasional “quick fix.” A 2005 review published in the Journal of Clinical Sleep Medicine concluded that the evidence for other herbal suppements (e.g., chamomile) was too limited to suggest any sort of benefit.
As far as safety goes, there’s not a lot of a good data out there. The most serious concerns appear to be related to L-tryptophan.
According to a recent report by ConsumerLab.com, an independent lab that randomly tests supplements and publishes reports on which products contain what they claim to contain, L-tryptophan fell out of favor (and imports were actually banned by the FDA) from 1995-2005 after a wave of consumers developed a serious medical condition (and a few dozen died) related to its use. U.S.-made supplemental tryptophan is now allowed again, but previous safety concerns should not be dismissed. In addition, L-tryptophan supplements should also not be used during pregnancy due to possible adverse effects on the developing fetus.
Melatonin in the doses described above appears to be safe in healthy people with no underlying neurological or psychological health issues. Pregnant women and people taking blood thinning medications should probably avoid it due to insufficient safety data.
Herbals like chamomile, valerian, lemon balm and passion flower should be perfectly safe. To the extent that there’s any benefit to be had from them, you may be better off taking them in an herbal tea before bed rather than in pill form, as the tea-drinking ritual itself may have a calming and relaxing effect that could help with falling asleep irrespective of the herbal ingredients themselves.
Overall, though, my recommendation is to save your money. There is such limited data to suggest a benefit and enough question marks regarding safety of some of these ingredients that taking a sleep supplement pill or beverage shot is probably not worth it.
Tamara Duker Freuman, R.D.