Why Am I Always Tired With PCOS, Even When I’m Doing Everything Right?

I already knew I had PMOS when I started looking this up. What I didn’t understand was why the tiredness felt so physical, mental, and so out of proportion.

I was taking magnesium glycinate for sleep, something I’d come across on TikTok and wanted to believe in. My sleep was all over the place; long work hours some nights, and other nights I kept the evening watching random stuff to shut my brain off, because it was the only part of the day that felt like mine. I was trying to cut sugar, but the post-dinner craving hit every single night and I usually gave in, inhaling whatever was in reach because it just felt so good. And the next day I’d show up to a 3pm meeting with brain fog so thick that I couldn’t think or see straight.

Finally one night I had three PubMed tabs open and a half-eaten packet of Oreos next to my keyboard. I work in finance, not medicine, nor do I have the patience and attention span for research journals, but I had been through enough cycles of this that I needed to understand what was going on.

This is what I found.

Quick note: this condition was officially renamed from PCOS to PMOS in May 2026. I use both terms here. PCOS because that’s what most people are searching for, PMOS because it’s the current name. I am not a doctor. This is personal experience, not medical advice.

What I Was Looking For

By 2025 my bloodwork had confirmed high cholesterol, dangerously high blood pressure, insulin resistance, vitamin D deficiency, and iron deficiency, on top of irregular periods that had been going on for years. Every single result came back as its own separate conversation with its own separate instruction: take this, monitor that, come back if things get worse. Nobody had ever looked at all of it together and asked what was driving it. There was no moment where a doctor said, wait, if this much is out of alignment at the same time, something is connecting these.

One GP in KL said I was stressed. Several other gynaes gave me some version of the same script: lose weight to manage the symptoms, take birth control, come back if things get worse.

None of them mentioned insulin resistance.

The frustrating part is that the insulin resistance had been sitting in my bloodwork the whole time. So this was not me inventing a theory at midnight because I was tired and over-Googling. There was real data in the bloodwork, like the fatigue, the cravings, the crashes, the irregular cycles, all of it pointing at the same thing. It had never been read altogether, only ever as a checklist of individual issues to fix.

According to the Endocrine Society’s PCOS patient information, insulin resistance is present in up to 70% of women with the condition, including lean women, a figure supported by systematic reviews in peer-reviewed literature. That was new information to me. I’d had PMOS for years and I had no idea what IR was and what it could do to my body, and before long it is 20 years of unchecked imbalances with my blood sugar.

That was on PubMed at 11pm and I sat with it for a while.

Why PCOS Fatigue Can Feel Like an Energy Crash

My reading kept coming back to three things, none of which my doctors had ever mentioned together:

Insulin resistance: how it affects whether your body can access the energy from food
Stress-response pathways: something to do with the HPA axis that I still don’t fully understand, but which seemed to explain the random wipeout days
Sleep quality: not only hours, but whether the sleep is doing what it’s supposed to

They don’t operate independently. That’s part of what makes this difficult to resolve.

On insulin resistance and the post-lunch crash

The research kept coming back to the same thing: insulin resistance disrupts how the body converts food into energy. When cells don’t respond to insulin properly, you can eat a full lunch and your body still can’t pull much from it an hour later. That explained the post-lunch slump.

I’d spent most of those years blaming the food, or the portion size, or the fact that I was not sleeping consistently. Once I paid attention to the timing, though, the pattern was hard to ignore.

I eat out a lot because I am usually too tired to cook. That means my meals are often carb-heavy in the normal Malaysian way: rice with something, nasi lemak, banana leaf rice, whatever is available between work and being exhausted. Nothing ever dramatic in terms of binge-eating, regular life and whatever’s accessible. Malaysia has amazing food, I love eating good food.

Right after lunch, the crash happens. My eyes and body feel heavy, my head foggy, and I spend the rest of the afternoon irritable and wanting a sugar or caffeine hit, anything to help me wake up and focus. Opening another spreadsheet on those days feels like a personal offence.

Knowing there was a reason helped. Not massively, but enough that I stopped reading those afternoons as proof I was doing something wrong. The numbers had been there for years. No one had used them to explain what I was feeling.

On stress-response pathways

I also went down a rabbit hole on the HPA axis, which is how the body manages cortisol under stress. I still can’t give you a clean explanation of the mechanism, I read it four times and it’s still fuzzy. What I took from it: in PMOS, the system can release more cortisol than the situation needs, cortisol raises blood sugar, and when insulin resistance is already there, your body handles that spike worse.

The weeks that made sense of it were always the high-pressure ones. Deadlines, long days, weeks where I was absorbing a lot at work, those were always the worst for cravings. I’d been putting it down to stress eating for years, which felt like a character flaw. Reading about cortisol and blood sugar changed how I saw it. I wasn’t stress eating because I had no self-control. My cortisol was doing what cortisol does when I’ve been under pressure for weeks.

It doesn’t make deadline week easier. But I stopped treating the cravings like a discipline problem on top of everything else.

On sleep quality

I’d been taking magnesium glycinate because it comes up constantly in PMOS communities, and it didn’t do much. What I hadn’t paid attention to was the month-to-month variation. Some months I sleep fine, some months I’m awake at 3am for no apparent reason, and the difference doesn’t seem to track anything I’m doing differently. I came across research linking PMOS with a higher risk of sleep issues including sleep apnea, which I hadn’t considered. You can log the hours and still not be getting what your body needs overnight. And if the inconsistency is hormonal, not behavioural, sleep hygiene advice is only going to go so far.

These don’t work independently of each other. The more I read the more interconnected everything looked. I went in wanting a single thing to fix and came out with a messier picture, more annoying, but at least the dots were starting to connect better now than at any point in the past 20 years.

Why the Usual Advice Felt Incomplete to Me

For years I treated the fatigue and cravings as a discipline problem: more consistency, fixed sleep times, stricter eating, push through the afternoon.

There were stretches where I did all of that. More movement, earlier nights when I could manage them, eating better food. It did not consistently work because I ran out of steam. Felt like an uphill battle every time.

Looking back, the approach was wrong. If insulin response and stress regulation are part of what’s happening, more effort doesn’t fix the problem. For me, it added load onto a system that was already overwhelmed.

Consistency never touches the actual problem when the problem is metabolic. I needed someone to tell me that before I spent three more years trying.

What I Changed and What I Noticed

I should say upfront: this is where what I did gets closest to advice territory, and I am not the right person to give that. What follows is what I changed and what I tracked. None of it translates directly to anyone else’s situation.

Eating protein first in the morning

Many TikTok nutritionists advise eating protein before carbohydrates to moderate the blood sugar response. That made sense to me, so that became the experiment. The mornings did feel more even after a few weeks. On the days I had a proper breakfast I felt satiated for longer and could push through without reaching for sugar. I can’t tell you whether that’s the mechanism, placebo, or something I haven’t accounted for. It’s going on the list for the next appointment.

Treating low-energy days as data, not failure

On the bad days I took it easy. No gym, lighter food, earlier to bed if I could manage it. I stopped pushing through every dip and stopped mentally tallying what I’d need to make up for the next day. It didn’t fix the crashes, but I stopped pinning guilt to those days.

Noticing the crash pattern

Not a formal tracker. I wish I could say I made a proper spreadsheet because that would be on-brand, but no. The pattern made itself obvious because it kept happening often enough to become annoying.

Carb-heavy lunch
A delay of about an hour
Body goes heavy, head goes foggy
Sugar craving that feels automatic, not chosen
Irritability with no obvious cause
Me trying to function through the rest of the afternoon like this is a personality/discipline issue

If any of this maps to your afternoons, bring it to someone who can interpret it. None of what I tracked is a protocol, and I am still waiting for the clinical read on some of it.

Consistency Doesn’t Fix a Moving Baseline

The wellness industry’s consistency framing assumes the system you’re applying it to is stable. Same input, predictable output. That’s a reasonable model, but I couldn’t apply it the same way with PMOS.

Insulin resistance means our baseline shifts, playing out completely differently depending on where we are in our cycle, what our cortisol has been doing, how much we’ve been managing that week. I was applying a consistency framework to a body that wasn’t equipped to handle it. Good habits are absolutely crucial to keep our already fluctuating baseline as steady as possible, but not when my mood and energy were already out of whack.

The useful shift for me was narrowing the success metric. I stopped measuring good weeks by whether I ticked a bunch of checkboxes (did I eat healthy, walk 10,000 steps, drink 2 litres of water, sleep by 10) and started measuring them by how quickly I recovered. A much lower bar, which is perhaps not the triumphant conclusion I was hoping for when I opened the first PubMed tab.

You Already Know Something Is Off

I don’t think effort is the problem. What I needed was someone willing to look at everything together and ask what was connecting it, instead of handing me another thing to fix separately, or give me birth control. I had to find that thread myself, and then figure out how to bring that information to the doctor in a way that didn’t seem like I was Dr. Googling everything.

If anything in here maps to your pattern, write it down before you go. Not as a self-diagnosis. So the question is specific enough to get past “have you tried losing some weight?”

Next: I changed what I eat first thing in the morning based on some of what I found in the insulin resistance research. The next post is what that looks like on a weekday when there’s no time and nothing in the fridge.

About the author: Sapna writes about PMOS and insulin resistance from the perspective of someone who figured most of this out alone, after years of being told her results were normal. She works in finance, is based in Kuala Lumpur, and is not a doctor or nutritionist. Everything here is her own research and experience, not medical advice.

This is not medical advice. Please speak with a qualified healthcare provider, ideally one familiar with PCOS and metabolic health, before making changes to your routine.

Last reviewed: Jun 2026

Sources: