How to Recover From Jet Lag (Sleep, Hormones & Circadian Rhythm Explained)

Jet lag doesn’t just affect your sleep—it impacts your circadian rhythm, hormones, digestion, and overall recovery after travel.

In this episode of Health Recoded, we break down what jet lag actually does to the body and how to recover faster when traveling across time zones.

If you’ve experienced poor sleep, brain fog, bloating, or fatigue after flying, this episode will help you understand why jet lag happens and how to support your body through it.

Jet lag is more than just feeling tired—it’s a form of circadian rhythm disruption that affects the whole body.

In this episode, I explain the science behind jet lag, what happens in your body when you travel across time zones, and practical strategies to recover faster.

In this episode, we cover:

- What jet lag is and why it happens
- How circadian rhythm disruption affects the body
- Why traveling east vs. west feels different
- How long it takes to recover from jet lag
- Why jet lag can cause brain fog, gut issues, and fatigue
- Practical lifestyle tips to reduce jet lag symptoms

If you’re looking to recover faster from jet lag, improve sleep after travel, and support your body while flying, this episode will give you a clear starting point.

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Chapters:

00:00 Intro
02:35 What is jet lag?
03:41 Is it worse to travel east or west?
05:00 How long does it take to recover from jet lag?
06:44 How jet lag affects the body
08:04 How jet lag affects hormones
12:46 Why jet lag causes brain fog
14:51 Why jet lag affects gut health
16:51 Why you get sick after traveling
17:44 How to recover from jet lag
25:32 Key takeaways

Resources:

- Sleep Foundation – Jet Lag Overview https://www.sleepfoundation.org/travel-and-sleep/jet-lag
- Doane, L. D., et al. (2010). Cortisol rhythms and jet lag https://pmc.ncbi.nlm.nih.gov/articles/PMC3089060/
- Paragliola, R. M., et al. (2021). Cortisol disruption and circadian rhythm https://pmc.ncbi.nlm.nih.gov/articles/PMC8263446/
- Zhang, L., et al. (2020). Brain effects of jet laghttps://pubmed.ncbi.nlm.nih.gov/32125068/
- Liu, Y. (2024). Circadian rhythm and hormone regulation https://academic.oup.com/sleep/article/doi/10.1093/sleep/zsae151/7706142
- Additional circadian rhythm research https://pmc.ncbi.nlm.nih.gov/articles/PMC4970552/https://www.nature.com/articles/s41467-022-33609-x

This content is for educational and informational purposes only and is not a substitute for guidance provided by your own medical professional.

Topics covered: jet lag, jet lag recovery, how to recover from jet lag, circadian rhythm disruption, jet lag symptoms, east vs west travel jet lag, sleep after travel, melatonin and jet lag, cortisol and jet lag, gut health travel, travel fatigue, how long does jet lag last

Transcript

SPEAKER_00 0:00

If you've ever felt foggy, bloated, anxious, or just not quite like yourself after traveling, that's not random. That's jet lag affecting your whole body. Hi, I'm Alex. I'm your nurse, and today we're going to talk about jet lag and how it affects your body. I personally just got back from a trip about a month ago, and I have only just recovered last week from the jet lag I was experiencing. I didn't realize just how much jet lag could affect your body. I always thought it was just adjusting a few hours and catching up on your sleep and maybe your melatonin being off a little bit, but experiencing the severity at which I did really taught me just how much the body is going through to transition during travel. It's not just losing sleep or being off by a few hours. It is your body literally adjusting to a complete change. You don't just have a sleep problem, you have a body clock problem when you're going through jet lag. I went to New Zealand and I'm in Phoenix, so that's roughly 20 hours difference ahead. And I kept thinking, oh, it'll only feel like a four-hour difference. It'll be okay. And let me tell you, it literally took me three weeks returning home after I came home for me to adjust. I came back home and I didn't give myself enough time to adjust to get back to work and just to acclimate back to my home. And everything just compounded it, just snowballed. And even if I was getting good sleep, I didn't feel like myself throughout the day. I would go to the gym and I wasn't pulling the same amount that I used to, or I would eat something that was normal for me and my gut would get all messed up, or I just genuinely it felt like I couldn't handle anything. I didn't feel resilient. I didn't feel everything just compounded and it just felt so big. All of these issues that I was dealing with in therapy were a 10 instead of a two. And I I genuinely just didn't feel like myself. And so experiencing that and the severity that I experienced it really pushed me to educate myself about this because I knew I was jet lagged, but it just didn't make sense about what I was experiencing. And once I started learning, I realized I wanted to learn more and I realized I wanted to talk more about this because I think it's important. So today we're going to shed some light on the subject and discuss what is jet lag, how does it affect the body, and how can we support ourselves and our bodies for a more peaceful transition. So the definition of jet lag, it is a circadian rhythm sleep disorder caused by rapid travel across multiple time zones. And it occurs when your internal biological clock is out of sync with the external environment or the light and dark cycle. So we're going to talk about this circadian rhythm a lot because that's the biggest point to understand with this. It is classified under circadian rhythm sleep-wake disorders. And so symptoms can include insomnia or difficulty sleeping or early waking up, daytime fatigue, reduced alertness, GI disturbances or dysregulation, mood changes, and then just generally not feeling like yourself. Like for me, I just didn't feel comfortable no matter what I did. Even if I went on a walk and did things that were normal for me, even if I was resting, I just genuinely didn't feel right in my own skin. And it was just weird. Jet lag is essentially a temporary mismatch between your internal clock and your external environment. So some key things to note about jet lag, it is worse going east than it is going west, which is not some I didn't realize that. I thought it was the opposite for whatever reason. But essentially the body is being forced to gain time and speed up the internal clock, which is harder than delaying it. So it forces your body going east, it shortens the natural cycle, and the you have to sleep and wake earlier than your circadian rhythm dictates. So this shortened day causes more severe jet lag compared to traveling west, which extends your day and aligns better with the body's natural tendency towards a slightly longer than 24-hour cycle. So, for example, if you were to go from LA to New York, that would be easier to adjust to. Sorry, opposite, New York to LA, that would be easier to adjust to because you just wind up having to stay up an extra three or four hours, however much that distance is, as opposed to if you went from LA to New York trying to force yourself to go to sleep at 6 p.m. instead of your normal at 10. The body doesn't want to wind down at that time. So your internal body clock is regulated by light and something called the superchiasmatic nucleus, which struggles to synchronize through the new time zone. Studies suggest a circadian cycle is actually slightly longer than 24 hours, making it easier to adjust to the longer day than the shorter one, like we were talking about. And it can take significantly longer to recover from eastward travel as well. So as a general rule of thumb, it takes roughly one day for every hour of time that you've adjusted to. So this is why sleep disruption can feel so intense, because that's kind of a long time to have to adjust, but your body doesn't shift instantly. So roughly one day for every hour. But for example, if you're traveling east, nine time zones, that could take about two weeks to adjust to, as opposed to eight or nine days, if you had done that the opposite and gone east to west. So it can almost double your time for recovery if you're going east instead of west. So your body doesn't just teleport with you, it has to slowly catch up. And something I also want to note, I'm talking about jet lag and traveling, but there is such a thing as social jet lag. So night shift workers or flight crews, where your circadian rhythm is just not in a continuous wake and sleep cycle, as with those of us who work nine to five or live in one place, or if it's just completely flipped, like with shift workers, you can experience these things that I'm talking about here, and this is still going on in your system. So that's why jet lag is classified as a circadian rhythm sleep wake disorder. It's not just travel, it's overall your circadian rhythm is off. So digging into the A and P, the anatomy and physiology behind how jet lag affects your body. We're gonna talk about a few key things: your circadian rhythm, hormones, how it affects the brain, the GI tract, and also how it affects the immune system. So the core concept is behind the circadian rhythm. The body runs on a 24-hour internal clock, which is, again, regulated by the superchiasmatic nucleus in the brain. Essentially, long term, I know, but this clock synchronizes your sleep-wake cycle, but it also affects your body temperature, your metabolism, and your hormones. And hormones are a big part of why you're gonna feel so off when you're experiencing this. So light exposure is the primary regulator of your circadian rhythm. We've talked about this previously. When you wake up in the morning, you get the bump of cortisol, and that gets you throughout the day, but then that decreases as light comes down and then the melatonin starts to increase, and that's what makes you sleepy. So your brain is still living in your old time zone when you travel, even though your body has physically arrived somewhere new. And that's why this can feel so disrupting. Your body thinks that it's 9 a.m. somewhere, but you're physically somewhere where maybe it's 9 p.m. and the two of you are out of zinc, and that can get really hard to deal with. So if we move into hormones, particularly cortisol and melatonin, but we are going to talk about female hormones as well. Cortisol follows a diurnal rhythm, just like I was saying, it peaks in the morning, and this is what helps you wake up, and it declines throughout the day. So, yes, cortisol is a stress hormone, but that doesn't mean that it's bad. If you're feeling stressed when you're not supposed to, yes, of course, but cortisol is natural. It's supposed to be higher in the morning and lower in the evening because it's trying to help you wake up and get out of bed and go on throughout your day. So jet lag disrupts this rhythm. So this leads to feelings of fatigue or poor energy regulation or stress dysregulation. Because your cortisol is firing at different times, you can feel wired in the wrong time. You're trying to go to bed and be tired, but it's wide awake because your cortisol and your hormones are still on a certain time frame. So essentially, you can feel wired when you should be tired and exhausted when you feel alert. And this is why, like for me, I felt so off and I didn't feel like myself, and everything was so stressful. I was 20 hours ahead. Like I was completely flipped. Even if I was getting good sleep during the day, my cortisol timing was off, and so I was just it was just constantly elevated, or it was not when it was should be high, it was low, and so everything just felt completely disaligned. So it makes sense. My body was stressed, and so therefore I was too. Talking about melatonin, this is an important one. It's a hormone produced in the brain's pineal gland, and it's in response to darkness. So where cortisol increases with light, melatonin increases with the darkness, and this acts as a signaling molecule that regulates the body's 24-hour clock or circadian rhythm, and then helps you feel sleepy and try to fall asleep. So it promotes sleep and it helps transition the body into nighttime mode. It can potentially offer antioxidant, neuroproductive, and reproductive system benefits. I think we need some more research on that, but I just want to make that statement. Um, but ultimately, again, released in response to darkness to help promote sleep. So jet lag delays or advances the melatonin release, which leads to those feelings of sleep disruption. So your body doesn't know when it's night anymore, and it doesn't know when it's day anymore, even if the light outside is cycling as it should. So menstrual and hormonal disruption. This one was kind of scary for me because I guess I won't go into TMI here, but mine was completely dysregulated and honestly still is. So let's make this a little bit less scary. Reproductive hormones are tied to circadian rhythm, progesterone, progress, progesterone, and estrogen. Jet lag disrupts the body's internal clock, circadian rhythm, which regulates hormones and frequently causes delayed early or missed periods. So if your body doesn't know what time it's at, for me, for example, I was 20 hours ahead, so then your hormones are off. So then your body's like, well, I guess we'll do this thing that we're normally supposed to do on this day, but I don't really know. So maybe we'll just do it anyways. So this disruption can affect your psychoregularity and the length. It can also affect your PMS symptoms and how painful your cramps are, making them more painful, and also because of that ovulation timing. So all of this is because of the circadian rhythm and it's up to the schedule of your body. So if your body is out of sync, then it makes sense that these things are not going to be firing appropriately. So maybe you're gonna experience a heavier flow or a longer period or again, heavier cramps, or other symptoms that you maybe wouldn't. Your body is completely dysregulated and it's just trying to get back to normal. Ultimately, this type of period delay is typically harmless. It will restabilize once you're back in your original time zone and your circadian rhythm has leveled out. It can take one to two cycles or periods, maybe even two to three months, for this to regulate. But ultimately, if your symptoms are completely abnormal or you're experiencing super heavy bleeding or clotting or pain, please reach out to your doctor or your OBGYN and get checked out for that. But I do want to say it can take a couple of cycles for this to regulate. So, how does jet lag affect our brain? It affects because again, circadian disruption, it affects attention, memory, and emotional regulation. So jet lag boosts your cortisol levels, which can affect your temporal lobe. And this is the region responsible for managing memory. So this is why you feel brain fog. So if your cortisol levels are out of sync and it's affecting your temporal lobe and it's not functioning as effectively as it should, you can feel foggy or fatigued. You're not quite like yourself and not easily able to recall memories or even make new ones. So jet lag disrupts the hippocampal-dependent memory and learning, and it decreases the cell proliferation in this area, which is the creation of new neurons in that area. And so this can make it hard to form new memories and cause a deficit in cognition. But I will make the disclaimer, this is typically with more chronic jet lag. So if you're a frequent flyer and you're constantly in jet lag or not really adjusting, or again, back to the night shift workers, if you're constantly out of sync, this could be why you maybe feel more fatigued more often or unable to recall different memories, or feel like you can't recall new ones. I was on night shift for nine months when I first started at the bedside as a nurse, and I genuinely do not remember certain parts of that. Now, granted, nine months is a long time to remember every single thing, but it was just I couldn't wait to get off of night shift. It was just not good for me, and it was something where I genuinely didn't feel like myself. When I'm up during the day, I felt great and I was fine, but when I had to switch and be up on night shift, I just couldn't think straight. I was fatigued, and it didn't feel like reality, to be honest with you. So that brain fog you feel, that's literally your brain operating out of sync. Moving on to the GI tract, this is gonna be a big one that you're gonna feel outside of all the other ones that we've already talked about. So the gut has its own circadian rhythm, which I found this to be really interesting. It's a 24-hour cycle of activity in the digestive system and its associated bacteria. So that microbiome that we talked about previously in the gut brain section, that's doing its own thing as well. Again, the enteric nervous system is the GI's own nervous system. It's doing its own thing. It's got its own brain down there and its own world and activity. So this circadian rhythm in the GI tract, it regulates digestion, nutrient absorption, and immune function, but it also acts as a peripheral clock that synchronizes its functions with the master circadian pacemaker of the brain. So essentially, it regulates all of these functions through your fasting and your feeding cycles. So when are you eating and when are you not? So the gut microbiota changes composition throughout the day based on what you're eating. Um, if you're eating breakfast at 8 a.m., it's gonna have its certain composition because it knows it's 8 a.m., it's breakfast time, this is what I'm supposed to be digesting, as opposed to dinner time. You're gonna be having this, or we're winding down for bed, or whatever it's experiencing. So it peaks in abundance during the morning or the night hours, or sorry, it peaks in abundance during the morning and then oscillates down for the night hours. And this is what we call diurnal oscillations. So digestion, nutrient absorption, bile acid metabolism, and peptide secretion are more efficient during specific times of the day, again, typically surrounding mealtimes. So disrupting this rhythm causes gut imbalance and it can feel just bloating or maybe you feel nauseous or irritable, whatever your specific GI symptom is. It's literally your gut microbiome being out of cycle and out of sync as well. Going into the immune system, and then we're gonna talk about some nursing tips for supporting your body through all of these symptoms that we're talking about. So, no surprise here, circadian rhythms regulate the immune function. This disruption in your circadian rhythm increases the inflammation and reduces immune deficiency. So your body is tired, it's dysregulated, and because of that, it's in a weakened state and it's more susceptible for infection because it's not nearly as able to fight off an infection or something else that may be attacking it, whether it be something from the GI tract, because again, the immune system and the GI tract are heavily connected. So your immune system runs on a clock as well, and when that clock is off, your defenses are too. So, how can we support our bodies going through all of this craziness? The biggest one is trying to get your sleep back in order. Light exposure is the strongest circadian reset signal. So in the morning, open your blinds, open your windows, your curtains, whatever, go outside for a quick walk, try to get some morning light exposure because this helps to shift the clock earlier, more naturally. So you're gonna get those cortisol bumps. That's hopefully gonna help regulate all those hormones that we talked about. And then in the evening, we're gonna turn down the lights a little bit early and try to let that melatonin bump. So light is medicine for your circadian rhythm. And talking about melatonin, this can help shift circadian rhythm timing, especially for eastward travel. So melatonin is one that I really wanted to talk about. It's best used for short term and timed correctly. A lot of people get this wrong where they take melatonin every night. That's not how you're supposed to use melatonin. It is a short-term endeavor. So roughly two to five days for jet lag or travel as you adjust. And depending on your needs, maybe 0.5 to 1 milligrams, maybe up to three milligrams depending on your needs. Ultimately, it is not a long-term endeavor for falling asleep. Your body can only metabolize roughly 10 milligrams of melatonin. So taking anything above that at once is essentially useless. Doses exceeding 10 milligrams are generally not recommended, but anything over 20 is actually considered really high and potentially unsafe. Taking too much can cause headache, fatigue, irritability, nausea, strange dreams. And if you're needing to take melatonin constantly, if you're having trouble falling asleep or staying asleep or getting enough sleep, please go see a doctor. Get a sleep study. That's the gold standard for figuring out what is going on, as opposed to just trying to medicate this. So melatonin is great in the short term. My recommendation be 0.5 milligrams to roughly one or three milligrams, again, depending on your needs. But uh take this as you travel or as you come back and adjust, and maybe two to five days, one to two hours before bed. Okay. Ultimately, this will ideally help to regulate the melatonin and the other hormones because if we're getting our sleep back in order, then everything else can start to adjust easily. So supporting our gut to adjust through jet lag, we want to try to eat meals aligned with local time because this is gonna help adjust the gut microbiome faster. So, for example, if you're taking a particularly long flight and they serve you a meal, a lot of times they will try to sync with where you're going. So if you're arriving in the morning, they'll try to serve you breakfast before you land, and then vice versa, if you're arriving in the evening. And so there's a reason behind this, it's try to to try to help you align faster than or sooner rather than later. Ultimately, as we're dealing with jet lag and trying to adjust, we want to prioritize fiber, but gently. I will call myself out here and say that I'm a bit of a fiber queen to the point of fault, and I've had to back off on that so I could allow my gut to adjust naturally. We want to hydrate as well to support the fiber that we are taking in roughly 64 ounces daily. And then probiotics are emerging support for circadian gut link. Um, you don't have to finish the course of probiotic that you take or take it long term. I started taking one and it was a 10 day course, and I didn't really like it. So I still have like two or three days left to take that. I don't think I'm going to. So I took maybe roughly what a week worth of the probiotic. And I do think it helped at first, but I kind of just don't think it was necessary beyond that, at least for me. I eat well enough in general. So If you already take a probiotic um long term, I know a lot of people are really crazy about probiotics, but if that's your jam, go for it. If you haven't ever tried it, give it a shot and see if it helps. But ultimately, we want to try to eat healthy items, eat at the times of day that we need to. So, like lunch at lunch, dinner at dinner, XYZ, and then ultimately help to synchronize our gut rhythm and then our sleep cycle so that we can just kind of let everything adjust. And part of the problem with this is these are supportive tips because this is just gonna take time. Um, nervous system support traveling overstimulates your nervous system. You're going to the airport and you're having all these bright lights and these loud speakers squawking at you, and people telling you what to do and what not to do. And for some people, flying can be really anxiety-inducing. And then you're going to a new place, and then maybe you have um never been to this place before and you don't speak the language, and so you have culture shot, and there's just you're getting a lot of stimulus, let alone if you come back home and then you're trying to clean your house or go back to work or get the growth, like you have this checklist of whether you're on vacation or whether you're coming back home to adjust, and that can just be a lot. So, what we're gonna try to do here is to support ourselves through these adjustments. So, breath work, meditation, reducing your stimulation at night if you can, maybe putting off requirements at least two to five days, depending on how long you need to adjust, how long you can allot putting things off, um, like special appointments or meetings or work or whatever. Try to give yourself two to five days after getting back from a trip, particularly a trip that was as big as mine, like the 20-hour adjustment. I went back to work like two days later, and I really should not have done that. I should have given myself at least three to four days to adjust, honestly longer, given that it took me three weeks to reacclimate to being back home. So you're not just tired, you are overstimulated and out of rhythm, and your body is trying to adjust. And so this makes sense why everything seems like too much, because it is. It's doing so much internally already that everything that is outside is just extra noise. So give yourself the peace and the patience to adjust and move through that. I really tried. Some moments were better than others, and I'm hoping I'll do better next time. This is a learning endeavor for me as much as it is for you guys. I did want to include some tips specifically for eastward jet lag. Um, the typical recommendations are to pre-adjust and also adjust your flight choice. So shift your sleep schedule an hour earlier each night for a few days before leaving, if you can manage that. So if you go to bed normally at 10, maybe start going to bed at 9 and then 8, and just kind of work your way up depending on how far you're going. And then also light exposure, seek bright morning light at your destination to help your body clock reset faster. And that's whether you're going on your trip or you're coming back home. And then for the flight choice, the recommendation is to opt for a daytime flight to avoid further disrupting your sleep. So that will hopefully help to adjust to the next time zone a little bit more easily. Ultimately, jet lag isn't just feeling tired after a flight. It's your entire body running on a different time zone, and that can feel really disorienting. It's a circadian rhythm disruption, not just fatigue, and it affects your brain, your hormones, your GI system, and your immune system. Your body needs time and cues, so light, food, sleep to readjust and realign. Supporting your rhythm and your body will hopefully help to achieve faster recovery. I hope this helped. I really needed this conversation about four weeks ago, and I'm really glad to be having it now. So I hope that it helps somebody else. If it does help you, please share it with someone else who could benefit. Maybe they just got back from a trip and they haven't quite adjusted yet or they don't really understand what's going on. Send any questions you have to me. I'm on Instagram. If you want to follow me at Health Recoded Podcast, I will answer questions either here in the comments or there. But ultimately, thank you guys for listening. I'll see you next week, and I hope this helped.