There are countless others herbal teas promoted as sleep aids however, including valerian, kava, passionflower, hops and lavender.
But do they really help you sleep better?
It's hard to know, because like many natural products, there's little solid evidence behind them, says chair of the Australian Sleep Health Foundation Professor David Hillman.
The level of supporting research behind different herbal sleep remedies varies from herb to herb.
The best results so far are for kava, passionflower, valerian and hops. But even for these, there's little convincing evidence they work as claimed.
In many cases, including chamomile, there's been virtually no quality research to make a judgement either way.
But interestingly, there is some evidence from clinical trials in humans that chamomile might help reduce anxiety.
Since anxiety is a common barrier to good sleep, it's feasible it could be shown to be helpful for sleep if tested properly. The same goes for Passionflower.
If sipping a herbal tea before bed is something you find pleasant and relaxing, and if good sleep follows, it's "a reasonable thing to do", despite the lack of firm evidence, Professor Hillman believes.
A wind-down ritual
Herbal teas might help sleep in a way that's quite separate from the herbs themselves too.
Filling the kettle, selecting your favourite cup, inhaling the fragrant steam and taking the time out from other activities to slowly sip your brew could be a useful wind-down ritual for bed.
In fact, watching the tendrils of colour of your favourite tea seep in to the boiling water might be just the sort of mesmerising activity your brain needs to shift gears before sleep.
And most herbal sleep remedies are unlikely to cause harm — so long as you don't take massive amounts.
There have been some safety concerns about kava though and for this reason it is available in only restricted doses in teabags and supplements in Australia. It has been linked with problems ranging from liver and kidney damage to breathing difficulties and skin ulcers.
Also, good studies about the safety of chamomile in pregnancy for instance are lacking, although it seems to be quite widely used by pregnant women, Professor Hillman says.
A low-risk choice
A cup of herbal tea is likely to pose fewer health risks than sleeping tablets, which can cause side effects such as dependence and shouldn't be taken for more than four weeks at a time. While there are some over-the-counter sleeping tablets, most require a doctor's prescription, anyway.
Herbal tea is also a better choice than coffee, which contains the stimulant caffeine.
Food and drinks containing caffeine are best avoided for four hours before bed, Professor Hillman says.
"If herbal tea stops you drinking a caffeinated drink before bed, it's a useful thing," he says.
The hot milk remedy
What about that other enduring folk remedy for insomnia — hot milk?
While again, there's little firm evidence, there are a number of plausible ways in which this old favourite might help sleep.
The digestion of milk in our guts produces substances called casomorphins, for instance, that have morphine-like properties and so may make you feel pleasantly drowsy and relaxed, Professor Hillman says.
Another idea is that a substance called tryptophan in milk can make you sleepy.
Tryptophan is an amino acid, one of the building blocks of proteins, and our brains use tryptophan to make serotonin, which helps regulate your sleep cycle.
A protein night cap?
But some research suggests milk or other foods containing tryptophan — such as turkey, cottage cheese, tofu and bananas — don't necessarily automatically make you sleepy.
When tryptophan is consumed in a protein-rich food, it seems other amino acids compete with tryptophan for entry into the brain.
Some experts have suggested tryptophan might enter the brain more readily when taken with starchy carbohydrates with a high glycaemic index — think white bread and jasmine rice.
"Some people do take a bit of comfort from a snack before bed, " Professor Hillman said.
But most of us don't need extra kilojoules and this is one reason to think twice before adding a bedtime milk and bread snack to your nightly ritual.
The best non-drug sleep remedies
If you're after natural ways to promote sleep, herbal teas and food of any kind aren't the top of Professor Hillman's suggestion list.
Changing your thoughts and behaviour around sleep is likely to have a far greater effect, he says. He suggests the following:
- make sure you allocate enough time in your schedule for sleep (for most of us, this means about 8-8.5 hours, including time to drop off)
- try not to wildly vary the time you go to sleep and the time you get up each day
- create a bedroom environment that's conducive to sleep (not too hot or too cold, fairly quiet and reasonably dark)
- have a wind-down routine before you go to bed (if you'd like that to include a cup of herbal tea or warm milk, that's fine)
- avoid stimulants prior to sleep (this includes not just coffee but vigorous exercise, and especially looking at a bright screen on your phone, tablet or laptop)
"Once these basics are in place, it's fine to explore things like herbal teas. But sipping chamomile tea while doing work on your laptop in bed before you head off to sleep isn't a good idea," Professor Hillman says.
There are some excellent self-help books and online resources that can help.
The Sleep Health Foundation lists some low-cost online sleep improvement programs you can try.
If you're still having trouble, it's worth seeing your GP, who may refer you to a sleep specialist or psychologist for help.
Also, you may have a sleep disorder such as restless legs syndrome, sleep apnoea or delayed sleep phase syndrome that requires investigation and treatment.