The "easy direction" that still knocks you flat
There's a comforting myth that flying west is painless. And it's true that westbound travel is easier than eastbound — your body would rather stay up late than go to bed early, and heading to Los Angeles asks you to do exactly that. But London to LA is an eight-hour shift, and eight hours is a big number in either direction. When it's midnight in Los Angeles, your London-set body clock is reading 8am and starting to fire up for the day. Do that in reverse and you get the classic LA jet lag pattern: bright-eyed at 3am, and fighting to keep your eyes open by mid-afternoon.
The flight itself is long — around eleven hours — and it's a daytime flight. You leave London late morning or midday and land in Los Angeles in the afternoon, having chased the sun west across the Atlantic and the whole of North America. That daytime timing changes your whole strategy compared to an overnight eastbound trip: on this one, you generally want to stay awake, not sleep the flight away.
Why westbound is the friendlier direction
Your internal clock naturally runs slightly longer than 24 hours, so lengthening your day feels more natural than shortening it. Flying to Los Angeles lengthens your day dramatically — you effectively get a 32-hour day of travel. Because your body is happy to drift later, most people adapt to westbound shifts at roughly a day per time zone or a little faster, versus the slower grind of eastbound recovery.
The entire game for London to LA, then, is about pushing your clock later: later light, later meals, later bedtime. That means seeking light in the LA evening and protecting yourself from waking too early in the LA morning.
Before you fly: drift later
In the three or four days before departure, nudge your schedule later. Go to bed 30–60 minutes later each night and sleep in as long as your life allows. Get bright light in the evening — stay up with the lights on, get outside late in the day — and go easy on very early morning light, which would pull you the wrong way. Even a couple of hours of pre-shift makes LA feel like a six-hour change instead of eight.
This is genuinely easier to do than the eastbound version, because "stay up a bit later and lie in" is a far more pleasant instruction than "go to bed early and get up in the dark."
On the flight: stay awake (mostly)
Because you land in Los Angeles in the afternoon or early evening, you want to arrive tired enough to sleep at a local bedtime. That means treating the eleven hours largely as waking time.
Set your watch to LA time at the gate. Keep the window shade up and stay in daylight — it's daytime the whole way, and light keeps you awake and helps drag your clock westward. Watch films, eat when meals are served, move around the cabin. Caffeine is more forgiving on this route than on an eastbound red-eye; a coffee in what is LA morning or midday is fine. If you genuinely can't stay awake, a single short nap is okay, but avoid a long deep sleep that leaves you wide awake at LA midnight. The aim is to step off the plane pleasantly tired and ready for a normal-ish evening.
Your first 48 hours in Los Angeles
Arrival afternoon/evening. You'll land into California daylight. Get outside and soak up that late-afternoon and evening light — it's exactly the signal a westbound arrival needs to push the clock later. Eat dinner at a local LA time, even though your body swears it's the small hours. Then push to stay up until at least 9–10pm local. This first night is the hardest: you'll be exhausted at 7pm and then, frustratingly, wide awake at 3 or 4am when your body thinks it's late morning.
Handling the 4am wake-up. Early waking is the signature symptom of westbound jet lag, and it's the thing to plan for. If you wake before dawn, keep the room dark — do not turn on bright lights or scroll your phone, because morning-type light will lock in the early waking. Rest quietly, use an eye mask, and try to doze. In the morning proper, delay bright light a little rather than rushing into it, and instead get your strongest light exposure in the afternoon and early evening to keep nudging later.
First full day. Get through it on daylight and movement. A walk outdoors in the afternoon does more than any amount of coffee. Keep caffeine to earlier in the day and stop by early afternoon so it's out of your system by night. Don't nap longer than 20 minutes. By the second or third evening the early waking usually softens and you start sleeping through.
Seasons and the California sun
Los Angeles is generously sunny year-round, which works in your favour — there's almost always ample afternoon and evening light to push your clock later. The main seasonal wrinkle is that in summer the long evenings make it easy to stay up (helpful), while in winter earlier sunsets mean you should be deliberate about getting outside in the afternoon while the light lasts. Either way, LA gives you far more usable daylight than a grey London winter, so the light half of the equation is easy here.
The bottom line
London to Los Angeles is a big eight-hour shift, but it's in the forgiving westbound direction. Drift your schedule later before you go, stay awake on the daytime flight so you can sleep at a local bedtime, and — most importantly — chase afternoon and evening light while guarding hard against pre-dawn light. Expect the first two nights to involve some early waking, then a steady improvement. Most people are sleeping normally by night four.