Which supplements to improve sleep?
Quick summary
Some food supplements shorten time to fall asleep by a few minutes; none maintains sleep all night the way a medicine does. In Switzerland, melatonin is classified as a medicine, not a supplement.
Key facts
Key points
- A food supplement can shorten time to fall asleep by a few minutes but does not treat insomnia that has been established for several weeks.
- In Switzerland, melatonin is classified as a prescription-only medicine and prohibited in food supplements (FSVO, art. 2 para. 4 of the former Swiss Food Supplements Ordinance) — unlike France or Germany.
- Magnesium improves sleep quality mainly in people in deficit; in individuals with normal status, the effect is not clearly superior to placebo.
- L-theanine taken at 400 mg per day for 28 days reduces perceived stress and light sleep in stressed adults (Moulin et al., 2024).
- An umbrella review published in February 2024 concludes there is no quantifiable evidence of valerian’s efficacy on insomnia, despite its very widespread use (Valente et al., 2024).
In Switzerland, 33% of adults report suffering from moderate or pathological sleep disorders according to the 2022 health survey of the FSO[9]. This pressure fuels demand for the food supplement aimed at sleep, within a Swiss regulatory framework that draws a strict line between medicine and nutrient. Understanding the proven benefits of food supplements on sleep means separating three audiences: occasionally disrupted sleepers, people with documented nutritional deficits and patients suffering from chronic insomnia. No molecule covers the three at the same time.
What can a food supplement do for sleep — and what can it not do?
Which effects are genuinely documented?
Three effects are firmly documented on the human body. Reducing time to fall asleep by a few minutes — melatonin, the sleep hormone, reaches its peak efficacy at 4 mg taken around 3 hours before bed, according to a 2024 meta-analysis covering 26 randomised trials[1]. Lowering perceived stress before bedtime (L-theanine, 400 mg per day), which can favour relaxation in anxious people. Correcting a magnesium deficiency that weighs on sleep quality. No molecule of a natural food supplement reproduces the effect of a hypnotic medicine on the whole night.
The observed effect remains moderate in most trials. On melatonin, the average reduction in time to fall asleep is counted in minutes, not tens of minutes, and the effect on total sleep duration is more discreet[1]. The improvement holds above all for people with a shifted circadian rhythm (jet lag, shift work), much less among long-standing insomniacs. Helping to improve difficult sleep onset remains a realistic goal; treating established insomnia is not.
Why a supplement is not enough in cases of chronic insomnia?
Chronic insomnia is defined by night-time complaints at least three nights a week for at least three months. At that stage, it is advised to consult a healthcare professional: clinical recommendations place insomnia-specific cognitive behavioural therapy (CBT-I) on the first line, not supplementation. A network meta-analysis published in JAMA Psychiatry in 2024 — which aggregates 241 randomised trials and more than 31,000 insomniac adults — confirms the reference status of CBT-I, in particular its sleep restriction and stimulus control components[8].
The mechanism stems from the very nature of established insomnia. Beyond a few weeks, the brain associates the bed, the bedroom and the evening rituals with wakefulness and the anxiety of not sleeping. No molecule undoes this learned conditioning: the problem goes beyond pharmacology and clinical research on this point is now solid. Only behavioural re-education plays that role, sometimes within a few weeks.
Which molecules have evidence to help you fall asleep faster?
Melatonin: why it is treated as a medicine in Switzerland
Melatonin shortens time to fall asleep by a few minutes on average, mainly in people with a shifted circadian rhythm[1]. It is used to treat jet lag and certain forms of wake-sleep desynchronisation. The effect on total sleep duration remains more modest, and that on night-time awakenings more debated according to meta-analyses. In short: it helps you fall asleep, it does not guarantee a complete night without awakenings, and its role in regulating the wake-sleep rhythm does not extend to all forms of insomnia.
In Switzerland, the FSVO prohibits melatonin in food supplements (art. 2 para. 4 of the former Swiss Food Supplements Ordinance)[10]. It is only available under the prolonged-release medicine Circadin, sold in 2 mg tablets, prescribed for primary insomnia in patients aged 55 and over, on prescription only. This is a fundamental difference from France or Germany, where melatonin is sold over the counter, in capsule or spray form, in products containing up to 1 mg per unit. Buying melatonin on a European site for use in Switzerland exposes the buyer to the legal status of a medicine imported without authorisation.
L-theanine: a documented anti-stress effect
L-theanine is an amino acid present in green tea. It does not act as a sedative but can favour relaxation: it reduces perceived stress, which can help anxious people fall asleep without causing daytime drowsiness. A Canadian randomised trial in 2024 on 30 stressed adults shows that at 400 mg per day for 28 days, it reduces light sleep measured by actigraphy and improves subjective sleep quality compared with placebo[3].
A 2024 systematic review covering 11 randomised trials confirms a beneficial effect of L-theanine as an adjuvant to treatments for anxiety disorders, attention-deficit/hyperactivity disorder and schizophrenia, at doses of 200 to 400 mg per day depending on the studies[4]. Good safety profile, no documented dependence, no next-day drowsiness. Limit: the trials cover small numbers and the exposure duration remains short. This relaxation effect does not replace treatment for generalised anxiety.
Which molecules to better maintain sleep over time?
Can magnesium really improve sleep quality?
Magnesium can improve your sleep quality mainly if you are in deficit. A randomised controlled trial in 290 insomniac diabetic patients published in 2024 shows a significant fall in insomnia severity after two months of supplementation with magnesium and potassium, associated with a rise in serum melatonin and a fall in cortisol[2]. In subjects with normal nutritional status, the effect is slimmer.
Doses studied: 200 to 400 mg of elemental magnesium per day, taken in one or two intakes. At equivalent dose, bisglycinate, a major ingredient in many sleep formulas, is generally better tolerated digestively than oxide, which is more laxative. A 2024 systematic review on restless legs syndrome retains magnesium oxide combined with vitamin B6 as the most effective combination to improve sleep quality and the severity of symptoms linked to this disorder[7]. Magnesium has no direct sedative effect: its role in neuromuscular regulation favours muscle relaxation that works in the background, without inducing drowsiness.
Tryptophan and 5-HTP: what the Swiss framework allows
5-HTP (direct precursor of serotonin, itself precursor of melatonin) is prohibited as an ingredient in food supplements in Switzerland, like melatonin and DHEA. L-tryptophan remains authorised under certain intake conditions[10]. This restrictive framework is reiterated by the FSVO in the official list of pharmacologically active substances not allowed: any imported formula must therefore be checked on the label, mention by mention, before use.
Scientifically, a 2024 randomised trial conducted in Singapore on 30 adults aged 66 on average reports a subjective improvement in sleep quality at 100 mg of 5-HTP per day for 12 weeks, but only in the subgroup of “poor sleepers” at the outset[6]. For a normally rested sleeper, the effect is not visible. In Switzerland, access to these molecules goes through a medical consultation and a magistral compounding in a pharmacy, outside the food supplement framework: this is useful information to know before ordering a product abroad.
What are sleep plants really worth?
Valerian, passionflower: between tradition and evidence
Valerian, like other relaxing plants, is studied for its beneficial effects on falling asleep. An umbrella review published in February 2024 in European Neuropsychopharmacology compiles eight systematic reviews on valerian extract and concludes there is a good safety profile, but no quantifiable evidence of efficacy on insomnia in objective measurement[5]. The improvements reported by users concern the subjective perception of sleep, not the latency or duration measured in the laboratory. This is a major nuance that mainstream communications, often carried by commercial phytotherapy, pass over in silence.
Passionflower and lemon balm — like chamomile — share a similar fate: long-standing traditional use, limited clinical data, placebo effect hard to isolate. That does not mean a natural product that contains these extracts serves no purpose: a subjective relaxing effect has real clinical value for mild disorders. But it does mean they cannot be presented as natural equivalents of a sleeping pill, as some online content does.
When to consult rather than supplement?
Three disrupted nights a week for one month already justify medical advice, not prolonged self-supplementation. Several signals should raise alarm: marked daytime fatigue, loud snoring followed by breathing pauses, morning headaches, repeated night-time awakenings, restless legs at bedtime. No food supplement treats sleep apnoea, an established restless legs syndrome, or an underlying anxiety or depressive disorder. Faced with these signals, consulting a healthcare professional is the right course of action.
Self-supplementation also has safety limits, with a non-negligible risk of side effects. Magnesium at high dose can cause diarrhoea, especially in oxide form. St John’s wort, sometimes added to “sleep and mood” formulas, interacts strongly with many medicines (anticoagulants, contraceptives, antidepressants). In case of pregnancy, these interactions require heightened caution. Systematically mentioning to your doctor or pharmacist the use of any supplement remains the basic rule.
Frequently asked questions
Is melatonin sold freely in Switzerland?
No, in Switzerland melatonin is a prescription-only medicine, not a food supplement. The FSVO prohibits it in supplements (art. 2 para. 4 of the former Swiss Food Supplements Ordinance) because of its pharmacological action. It is marketed under the prolonged-release medicine Circadin, prescribed for primary insomnia in patients aged 55 and over. This restriction sets it apart from France and Germany, where it is available over the counter at up to 1 mg per tablet. Buying melatonin online from outside Switzerland to consume it here counts as an importation for personal use, at one’s own responsibility.
How long does a supplement take to act on sleep?
The effect varies strongly according to the molecule. On falling asleep, L-theanine can act from the very first intakes; by contrast, the effect on overall sleep quality is only measurable after 14 to 28 days in clinical trials. Magnesium follows the same logic: 2 to 4 weeks of regular use are needed before assessing any benefit, especially in cases of prior deficiency. If no improvement is felt after 4 to 6 weeks at an effective dose, supplementation alone is probably not appropriate and medical advice is required.
Can you combine several supplements to sleep better?
Yes, but with caution and ideally on a pharmacist’s advice. Magnesium plus L-theanine combinations are the most frequent and rest on different mechanisms (neuromuscular regulation and anti-stress), so they are plausibly complementary. By contrast, stacking sedative plants together (valerian, passionflower, lemon balm, hops) mainly increases the risk of adverse effects with no demonstrated benefit. Combinations containing St John’s wort should be avoided without medical advice: they interact strongly with anticoagulants, oral contraceptives and antidepressants.
Do food supplements create dependence like sleeping pills?
No physical dependence is documented for magnesium, L-theanine, valerian or other supplements commonly sold in Switzerland for sleep. This is a major difference from benzodiazepines (Lexotanil, Temesta) or Z-drugs (zolpidem, zopiclone), which can generate tolerance within a few weeks. Psychological dependence remains possible — the evening supplement ritual becomes reassuring in itself. If stopping is accompanied by anxiety at bedtime, the perceived benefit probably owed more to the placebo effect than to the molecule.
When should you consult rather than supplement?
As soon as the disorders persist at least three nights a week for more than a month, or in case of warning signs. The signals that should send you to the doctor: loud snoring followed by breathing pauses (possible apnoea), morning headaches, daytime fatigue incompatible with normal activity, restless legs at bedtime, dark thoughts or invasive anxiety. No food supplement treats sleep apnoea, an established restless legs syndrome, or depression. The consultation remains the safe route to identify the real cause.
Sources and references
10 sources- Cruz-Sanabria F. et al. (2024). Optimizing the Time and Dose of Melatonin as a Sleep-Promoting Drug.
- Khalid S. et al. (2024). Effects of magnesium and potassium supplementation on insomnia and sleep hormones in patients with diabetes mellitus.
- Moulin M. et al. (2024). Safety and Efficacy of L-Theanine Supplementation for 28 Days in Healthy Adults with Moderate Stress.
- Moshfeghinia R. et al. (2024). The effects of L-theanine supplementation on the outcomes of patients with mental disorders.
- Valente V. et al. (2024). Does valerian work for insomnia? An umbrella review of the evidence.
- Sutanto C.N. et al. (2024). The impact of 5-hydroxytryptophan supplementation on sleep quality in older adults.
- González-Parejo P. et al. (2024). Effects of Dietary Supplementation in Patients with Restless Legs Syndrome.
- Furukawa Y. et al. (2024). Components and Delivery Formats of Cognitive Behavioral Therapy for Chronic Insomnia in Adults.
- Federal Statistical Office. Sleep Disorders Indicator — Swiss Health Survey 2022.
- Federal Food Safety and Veterinary Office (FSVO). FAQ Food Supplements in Switzerland.