Last updated: December 2025
Written by Dr James Knox, Director of Glide Online Travel Clinic
You’ve been living your best life in Europe – strolling cobblestone streets, learning Italian and eating lemon-zest pasta by a sparkling Mediterranean. But the moment you get back to Australia? You’re falling asleep at 3pm, wide awake at 3am and hitting the espressos just to function.
Jet lag hits harder on the way home from Europe, Africa, the Middle East and parts of South East Asia – and there’s a biological reason for it.
Why Coming Back is Harder
Jet lag happens when your internal body clock (your circadian rhythm) gets out of sync with the time zone you’ve landed in. And it doesn’t just make you sleepy, it affects your digestion, hormones and mood.
And – it’s worse when you travel east.
Your Body Clock 101
Light is the master controller of your body clock. A tiny region at the centre of your brain called the suprachiasmatic nucleus (or SCN) acts like your internal timekeeper, responding directly to signals from light exposure through the eyes. When light hits your retinas – especially bright, natural light in the morning – it sends a powerful signal to the SCN to reset your circadian rhythm.
This affects everything from sleep timing and digestion to hormone levels, including the natural rise and fall of melatonin, a hormone that helps regulate sleep. Bright light in the late evening can delay the onset of this natural melatonin rise, keeping you wired when you should feel sleepy.
Why Direction Matters
When you travel east, your body has to fall asleep and wake up earlier than it wants to. And that’s harder than staying up late and sleeping in, which is what westward travel asks you to do. Pulling an all-nighter is tough, but falling asleep five hours earlier than usual? Almost impossible.
Jet lag starts becoming noticeable once you cross more than two time zones. But the real sweet spot for trouble is moving east by around five to eight time zones – common for return trips to Australia from places like Dubai, Istanbul, Rome, or Athens.
That’s where many travellers get stuck in limbo – it’s 8am in Australia, but your body thinks its midnight to 3am.
What You Can Do
Here are some helpful strategies:
1. Make a plan
Travelling east by seven times zones or less, for example from Athens or Istanbul to Sydney, you are generally better off trying to bring your bedtime forward. Moving east by eight or more time zones, like Rome or London to Sydney, you have the option of attempting to push your bedtime back, through the whole day.
2. Adjust incrementally if you can
If you’re travelling east, and your home schedule allows it, change your bedtime just a few hours each day. This can ease the blow and gives your body time to adjust its existing rhythms rather than having to produce entirely new ones.
If you need to go all out, you can start making small adjustments to your bedtime and wake-up time before your departure. But my approach in most situations is to start adjusting my body clock as I board the plane.
I set my watch to the time at my destination and begin timing my meals, sleep and light exposure to incrementally move to the new times.
3. Use light like a reset button
Your body clock is deeply influenced by light – when you get it, and when you avoid it.
- Aim to get some morning light. If you’ve just travelled six or seven time zones east, make this late morning and get progressively earlier.
- Sunlight is best, so grab a coffee and sit outside if you can.
- Spend time outdoors during the day.
- When you sleep at night, keep the room as dark as possible, even if you’re not sleeping well.
On the flight, the airline crew will usually manage the window shades with this in mind. On top of this, an airline-issue eye-mask is a great way to keep the light out.
4. Be strategic with caffeine
That 8am cappuccino can be your best friend – but anything caffeinated after 2pm? It’s likely to sabotage your night’s sleep. Keep coffee as a morning tool.
5. Nap smart, not long
A short nap (20 to 30 minutes) can help you power through the afternoon slump – just try to do it at least eight hours before bedtime. Find a sunny park or a place to lie down in the backyard. And set a loud alarm.
6. Eat at local mealtimes
Even if your stomach says, ‘it’s midnight’, eating meals on the new local schedule helps train your body to adapt. Try to stick to three meals a day and aim to keep it light and healthy.
7. Give yourself grace
Your body adjusts at a pace of about one to one-and-a-half time zones per day. So if you’ve crossed seven time zones, you might not feel normal for a while – and that’s okay.
8. Get an expert in your corner
If part of your trip involves crossing seven or fewer time zones heading east, there are other specific strategies that may assist in gently shifting your body clock. So consider seeing a doctor before you go, particularly if you’ve struggled with jet lag in the past.
Final Word
Jet lag isn’t just ‘being tired’ – it’s your entire system recalibrating after moving halfway across the planet. And yes, it’s usually worse when you come back to Australia because you’re often flying east, across a jet-lag sweet spot of five to eight time zones.
The good news? A little planning, some sunshine at the right time, and smart choices around sleep, meals and caffeine can make a huge difference.