Dehydration on Foundayo: What People Say About Thirst, Fluids and Feeling Dry
Foundayo (orforglipron) is a once-daily weight-loss tablet, and one of the quieter themes in the forums that have grown up around it is water. People write about forgetting to drink, about being unusually thirsty, about headaches they put down to not drinking enough, and about the odd experience of feeling dehydrated while sipping all day.
The word "dehydration" is used loosely in these threads. Sometimes it is a diagnosis from a doctor or a hospital, and sometimes it is only a hunch about a headache or a tired afternoon. These are personal accounts, so they cannot show how common any of this is or what is behind it.
What follows is a look at how people describe it, in their own words: what happens to thirst, what they think they notice in their bodies, what they say they tried, and the few accounts that went well beyond a dry mouth.
When the Thirst Seems to Go Quiet
For a number of people the first surprise is not that they feel dehydrated but that they have stopped noticing what they would normally reach for. One person on 2.5mg, in the middle of a hot summer, described the appetite and the thirst fading together.
"And so is my thirst. With it being so hot I have to drink water and I am not doing that as much."
– tababnaba76
The change can be subtle enough to go unnoticed for weeks. A person who had moved over from another tablet only realised how little they had been drinking once they looked back at it, and the clue was something that had been missing all along.
"didn’t realize I didn’t drink enough water bc I was never thirsty"
– Letstalkabouttax_111
At the other end of the day, a first-day account from someone new to this kind of medicine links the two things plainly: a very small appetite and a lapse in routine drinking.
"I think in my case it reduced so much I was struggling to keep up with regular meals and water intake."
– Smart-Toe-8752
And for Others, the Opposite
Not everyone's thirst fades. A smaller group describe the reverse, a constant pull towards water that changes the shape of their day, and in one case the day's schedule.
"I'm shocked at how thirsty I am on Foundayo so far. Doing like 120 ounces a day right now between the Foundayo and daily sauna and peeing all the damn time."
– GoodProbsToHave
The same note appears in much shorter form elsewhere. In a thread started by a newcomer, one reader on the lowest dose listed what had not happened to them before adding the one thing that had.
"No constipation. No stomach issues. I just get thirsty."
– Change_Soggy
Feeling Dehydrated While Drinking
The most puzzled accounts come from people who were already careful. In a long thread started by someone nearly seven weeks in, the original poster had always been a heavy water drinker, and that was exactly what made the new feeling hard to explain.
"I have always been someone who drinks a lot of water and stays hydrated, so I wasn’t really worried about that when starting a glp1. However, I am SO dehydrated all the time now and I don’t feel like there’s been a huge reduction in how much water I’m drinking?"
– Ok-Sandwich2365
The replies offered several readings. One reply, from someone who did not name the medicine they take, put forward the idea that the thirst signal itself may be dulled, which would make the sense of how much has been drunk unreliable.
"The meds suppress your thirst as well as your hunger so it may well be that you aren’t drinking as much as you think you are, tracking should be helpful."
– ClientCheap5887
Others in the same thread were more practical than theoretical. One described a split between plain water, which on some days would not go down, and the same water with electrolytes added.
"There are some days were I just can't get plain water down (I hardly ever knew this issue before glp1), but when I add electrolytes, it becomes effortless."
– embroideredyeti
The thread never settles on a single explanation, and several replies suggested the poster mention it to their doctor. What it captures is how hard it is for someone to tell, from the inside, whether they are drinking too little or simply feeling different.
Headaches, Tiredness and the Fluid Question
Headaches and fatigue are the symptoms most often tied to dehydration in these threads, usually in the first days. The link is nearly always a personal judgement rather than something anyone has tested. One person who counted a headache among their first-day experiences was confident about the cause.
"My first day I got a headache from dehydration."
– Careless-Two2215
Others were more tentative. A week-one diary from someone who had used Mounjaro before, heavy on nausea, ended its headache paragraph with a plan rather than a conclusion.
"I've also had fairly constant migraines/headaches this week, which may potentially be linked to being slightly dehydrated, so I'm going to make a conscious effort to increase my fluids."
– EducationalTune870
Hesitation is common when tiredness is the symptom. Someone describing tiredness in the second week of treatment guessed at a cause and then, in the same breath, took the guess back.
"It might have been from eating so little and getting dehydrated the first week, I don't know."
– HalleFreakinLujah
Then there are those who rule it out. Another person on day six, flat after a few days on the lowest dose, had already considered the idea and put it aside.
"I hydrate through the day a lot. So I can’t imagine it’s dehydration."
– NotNotKatieHolmes
What People Say They Do About It
Beyond headaches and thirst, the accounts turn practical, and they come from people who have clearly thought about their own habits. One began with a lesson from an earlier medicine, and it was less about the amount of fluid than about what counted as fluid.
"I’m stressing the water I’m drinking because I learned a huge lesson while taking the Wegovy shots: diet soda does not equal water. I believe at least part of my persistent nausea issue was my dehydration level."
– Finnatically
Another had a short experiment to report on headaches in the first week, with a result that, in their telling, arrived quickly.
"I had bad headaches the first 5ish days. I upped my water intake and added electrolytes and am no longer getting headaches so that’s been a huge relief."
– darkblueshapes
Neither is a recommendation, and neither shows what actually changed. They show how much of this is trial and error, carried out by people who are watching their own bodies closely.
When Fluids Are Lost
A different set of stories is about fluid leaving the body quickly. One person on the 2.5mg dose had loose stools almost every day after the step up, and listed everything they were doing to look after themselves, only to end on a question.
"I eat a ton of protein, a ton of fiber, drink 100oz of water a day, even drink some electrolytes. Not overeating. Not drinking alcohol. Not eating fatty or spicey foods. Small meals throughout the day. So doing all the things."
– SweetAwareness0504
The most serious account in the threads belongs to another medicine, but the person had moved to Foundayo afterwards and wrote about the earlier episode in the same comment. It is the one place where the word dehydration came with an emergency department attached.
"For 6 days I couldn't keep anything down. One day I only ate half a gram cracker and another day 2 spoonfuls of yogurt before I lost it. Doctor told me to go to the ER due to severe dehydration."
– AbrocomaFlat6832
The two stories are quite different in scale. One is a persistent annoyance in the middle of a routine, the other a week that ended with hospital care, and the forums treat them as part of the same conversation.
Dizzy Spells and Two Readings
Feeling faint is the symptom that most divides the threads. Someone seven weeks in who had decided to stop described exertion that left them close to passing out and weak for hours afterwards, and had a theory of their own about it.
"I figured the BP meds were the primary reason for the lightheaded/fainting feeling when exerting myself in any way, and I have a follow up with my PCP in 2 weeks where I plan to discuss adjustments."
– donle215
A stranger replying to their original post, which described the same symptoms, read them quite differently.
"all of these symptoms could be reasonably attributed to dehydration and electrolyte deficiency."
– serglonkofdonk
Neither reading is confirmed anywhere in the thread, and the original poster's plan was to raise it at an appointment. Dizziness and tiredness turn up in so many accounts, with so many different suspected causes, that it is rarely clear to the people posting what belongs to what.
What Does Medino's Pharmacist Think?
"What strikes me in these accounts is how often fluids, appetite and how someone feels get tangled together. A headache, a tired afternoon or a dry mouth can mean several things, and people are reaching for the word dehydration partly because it is a word they have heard. The experiences vary a lot, from people who feel more thirsty to people who say they barely notice thirst at all."
– Alessandro Grenci, Pharmacist at Medino
A Word With Many Meanings
Taken together, these accounts do not describe one experience called dehydration. They describe a quiet thirst, a loud thirst, headaches with a suspected cause, tiredness with a doubted one, a few frightening episodes and a great deal of improvisation with bottles, tumblers and electrolyte powders.
What links them is attention. People on a new medicine are watching their own bodies more closely than usual and trading notes with strangers who are doing the same, and water, it turns out, is one of the things they watch.
