When you fly across multiple time zones, your internal clock (your circadian rhythm) is suddenly still operating on the old time. That misalignment causes the grogginess, sleep trouble, fatigue, and general “off-ness” we call jet lag. Here’s what the research says actually helps, and how to use those strategies.
What Science Tells Us
Scientific studies (clinical trials, reviews, chronobiology research) show that the most effective cures involve resetting your body’s clock through light exposure, melatonin, and planning. Other strategies help minimise symptoms while your body adjusts.
What Actually Works
Here are the key strategies that are backed by good evidence:
| Strategy | What to Do | Why It Helps | Things to Watch Out For |
|---|---|---|---|
| Light Exposure (Natural or Bright Light Therapy) | Expose yourself to daylight at times aligned with the new time zone. If traveling east, morning light helps. If traveling west, afternoon light is better. You can also use light boxes if outdoor light isn’t possible. | Light is the strongest cue your internal clock uses to synchronise with environmental time (day/night cycle). Proper exposure helps shift your circadian rhythm faster. | Light at the wrong time can make things worse (delay adjustment). Also, very bright light might be uncomfortable; sunglasses or dim lighting might be needed in transition. |
| Melatonin Supplementation | Take low doses (often 0.5-5 mg) at the bedtime of your destination for a few days, or timed before travel when going east. | Melatonin is the hormone your body makes to signal night and sleep. Supplementing at the right time helps shift your sleepiness and internal clock toward the destination time. | Timing is critical—too early or too late and it can shift your clock in the wrong direction. Possible side effects: grogginess, occasional stomach upset. Also, in some countries it’s regulated differently, so check legality and quality. |
| Adjusting Sleep and Wake Before Travel | Gradually shift your sleep/wake times, meal times, and light exposure a few days before your trip toward the new time zone if possible. | This “pre-adjustment” gives your body a head start so there’s less shift needed after you land. | Sometimes not practical (work, family, etc.). Also, large shifts (many time zones) are harder to compensate for perfectly. |
| Hydration & Avoiding Alcohol/Caffeine at the Wrong Times | Drink plenty of water during travel. Limit or avoid alcohol (especially close to bedtime), and moderate caffeine (use it to stay alert but avoid it near sleep time) especially on arrival. | Dehydration and substances like alcohol worsen sleep disruption. Caffeine can help during the day but worsen sleep if mis-timed. | Everyone reacts differently to caffeine and alcohol. Also, quality of hydration depends on personal health, plane cabin conditions, etc. |
| Strategic Naps & Sleep Hygiene | If you arrive and are very sleepy, a short nap (15-30 min) can help. Make your sleeping environment comfortable (dark, cool, quiet). Use sleep accessories if needed (eye mask, ear plugs). | Helps reduce extreme fatigue without messing up nighttime sleep. Good sleep hygiene supports quicker adjustment. | Long naps or napping too close to bedtime can delay sleep onset at night. Be disciplined about nap length. |
A Sample Plan
Here’s how you could combine the strategies for a flight that crosses, say, 6-7 time zones eastward:
- 3–4 days before departure: Start going to bed and waking up ~1 hour earlier each day.
- On travel day and arrival:
- Switch your watch and meal times to the destination time as soon as possible.
- Try to sleep on the plane if it’s nighttime in the destination.
- Upon arrival, seek morning light soon after waking. Avoid bright light in the evening.
- Take melatonin 30-60 minutes before your bedtime in the new time zone for a few nights.
- Stay hydrated, eat lighter meals in the evening, avoid alcohol close to bedtime.
- If very tired, take a brief nap in the early afternoon only.
Most people following a plan like this find their adjustment is smoother and symptoms lessen more quickly. Research suggests recovery of ~1 day per timezone for many, but good prep and correct light/melatonin timing can reduce that.
Caveats & What Doesn’t Work
- There is no “magic pill” that instantaneously fixes jet lag. Even melatonin helps, but only when used properly.
- Using sleep aids / sedatives can help for sleeping during travel or the first few nights, but they don’t correct the underlying circadian misalignment. They also carry risks of side effects.
- If you’re crossing many time zones, going east is harder than going west (because advancing the clock tends to be harder than delaying). It takes more effort/planning.
- Individual differences matter: age, general health, how much natural light you’re exposed to, your chronotype (“morning person” vs “evening person”) will affect how fast you adjust.
Bottom Line
Jet lag is almost always temporary and treatable — you don’t need to suffer through every flight. By using light exposure, melatonin, and smart scheduling (before, during, after), you can ease the symptoms and help your body reset more quickly. And even simple behavior tweaks (hydration, naps, avoiding alcohol, aligning meals) can make a noticeable difference.
