Jet lag tablets

Jet lag is a temporary sleep disorder that happens when your body clock becomes out of sync with the time zone you are in. It is most common after long flights that cross several time zones and usually improves within a few days as your body adjusts.

What causes jet lag?

Your body follows a natural rhythm, known as the circadian rhythm, which controls when you feel awake or tired. When you travel across time zones, this rhythm no longer matches local day and night, leading to symptoms of jet lag.

Factors that can make jet lag worse include:

• crossing several time zones in a short time
• travelling from west to east
• long periods of sitting during a flight
• differences in daylight hours at your destination
• multiple layovers or extended travel times

Symptoms of jet lag

Jet lag can affect sleep, energy levels, digestion, and mood. The symptoms can vary, but common issues include:

• difficulty falling asleep at night
• waking up too early or too often
• poor sleep quality
• daytime tiredness or exhaustion
• problems with concentration and memory
• irritability or mood changes
• headaches
• upset stomach, nausea, or constipation

How common is jet lag?

Jet lag affects most people who travel long distances across time zones, although the severity can differ. Some people may notice symptoms after crossing 1 or 2 time zones, while others may adapt more easily. Symptoms generally improve within a few days without treatment.

Jet lag tablets contain melatonin, a hormone that helps regulate your body’s sleep-wake cycle. By increasing melatonin levels, these tablets signal to your body that it is time to sleep. This makes it easier to adjust to the new time zone after long-distance travel.

What is melatonin?

Melatonin is produced naturally in the brain as daylight decreases. It tells your body to prepare for sleep and plays an important role in regulating circadian rhythms. Melatonin tablets work in a similar way, helping your body clock adjust more quickly when travelling.

How to take jet lag tablets

It is important to follow the instructions carefully so the tablets work properly and safely. The guidance below is based on the patient information leaflet.

Recommended dose for adults:

• take one 3mg tablet at bedtime on arrival for up to 5 nights
• if needed, 2 tablets (6 mg) may be taken together
• only take between 20:00 and 04:00
• swallow whole with water, do not crush or chew
• avoid food for 2 hours before and after taking

How effective are jet lag tablets?

Melatonin can reduce symptoms of jet lag and improve sleep after crossing time zones. In clinical trials, 9 in 10 people taking melatonin at bedtime reported reduced jet lag symptoms

Common benefits include:

• falling asleep faster at night
• fewer early morning awakenings
• better overall sleep quality
• less daytime tiredness and irritability

How long does it take for jet lag tablets to work?

Melatonin tablets are usually slow-release and begin to work within 1 to 2 hours of taking them. Most people find their sleep improves within the first few nights of use. Tablets should be taken for up to 5 days after arriving at your destination.

You need a prescription to buy jet lag tablets in the UK. Melatonin is the only medicine licensed for short-term treatment of jet lag. You can order it online after a medical consultation, or collect it in person once your prescription has been approved by a doctor.

Can I buy jet lag tablets online?

Yes. You can buy jet lag tablets online from ZAVA after completing a medical questionnaire. A doctor will review your answers and prescribe melatonin if it is suitable for you. Once approved, your treatment can be delivered to your home address or you can collect them from a Post Office.

Can I get jet lag tablets over the counter?

No. You cannot buy melatonin tablets for jet lag over the counter in the UK. They are prescription-only medicines, so you will need to complete a consultation with a doctor or pharmacist before treatment can be provided.

Can I get jet lag tablets on the NHS?

Melatonin is not usually prescribed on the NHS for jet lag. This is because there is limited evidence on its effectiveness, and most cases of jet lag improve naturally within a few days. Private services can prescribe melatonin if your doctor agrees it is suitable.

Like all medicines, jet lag tablets can cause side effects, although not everyone will get them. Most side effects are mild and short-lived, improving within a few days as your body adjusts. Some side effects are less common but may require medical advice or treatment.

Common side effects

These may affect up to 1 in 10 people and include:

• headache
• drowsiness or feeling sleepy during the day
• dizziness
• irritability or mood changes
• dry mouth
• feeling sick (nausea) or stomach upset

Uncommon side effects

These may affect up to 1 in 100 people and include:

• high blood pressure
• anxiety or restlessness
• abnormal dreams
• skin rash, itching, or dry skin
• indigestion or abdominal pain
• mouth ulcers
• weight increase

Rare side effects

These may affect up to 1 in 1000 people and include:

• blurred vision
• memory problems
• fainting
• disorientation
• changes in mood or behaviour
• unusual bruising or bleeding
• prolonged or painful erections in men

How long do side effects last?

Most mild side effects, such as headaches, drowsiness, or stomach upset, usually improve within a few days of starting treatment. If symptoms continue for more than a week or get worse, you should stop taking the tablets and seek advice from your doctor or pharmacist.

What to do if you get side effects

If you experience any side effects, you should:

• stop taking the tablets if side effects are severe or persistent
• speak to your doctor or pharmacist for advice on managing mild symptoms
• seek urgent medical attention if you notice serious problems such as chest pain, allergic reactions, unexplained bruising, or sudden mood changes

Jet lag tablets are suitable for many adults, but they are not right for everyone. Certain health conditions, medications, or life stages mean melatonin may be unsafe or less effective. Always complete a consultation with a doctor before starting treatment for jet lag.

Who should not take jet lag tablets

You should not take melatonin for jet lag if you are:

• under 18 years old
• pregnant, planning a pregnancy, or breastfeeding
• allergic to melatonin or any other of the tablet's ingredients

Medical conditions to discuss with your doctor

Tell your doctor if you have, or have ever had:

• epilepsy
• autoimmune diseases such as lupus or rheumatoid arthritis
• diabetes or glucose intolerance
• liver or kidney problems
• depression or other mental health conditions
• problems with fertility or are planning a baby

Medicines that may interact with melatonin

Melatonin can interact with certain prescription and over-the-counter medicines. You should inform your doctor if you take:

• fluvoxamine (for depression or OCD)
• psoralens (for skin disorders such as psoriasis)
• cimetidine (for stomach ulcers or acid reflux)
• quinolones or rifampicin (for bacterial infections)
• carbamazepine (for epilepsy)
• blood thinners such as warfarin
• sedatives or sleeping tablets

Important: There is a small possibility that hormone treatments containing oestrogen, such as the combined contraceptive pill or HRT, can increase the effects of melatonin. You can still use melatonin, but you should be aware of this possibility. Melatonin does not affect how your contraceptive pill or HRT work.

Safety advice

Melatonin can cause drowsiness, so it is recommended not to take it before driving or operating heavy machinery. If you are a smoker, be aware that tobacco smoke may reduce the effectiveness of melatonin by breaking it down faster in the body.