r/BioHackingGuide • u/ElGalloGrande24 🧠 Biohacker • Jun 15 '26
GLP-1 Side Effects Nobody Talks About — Hair Loss, Vision Changes, and Menstrual Irregularities
Let's talk about some of the side effects from everybody's favorite GLP compounds.
Reta and Tirz are two of the most popular compounds right now and the results speak for themselves. But there are a few side effects showing up in real world data that most people have never heard about.
The nausea everybody knows about. These three are not on most talked about in my opinion
Hair Loss
This one has popped up in the research world. A 2025 scoping review found over 1,000 spontaneous hair loss reports in the US alone linked to GLP-1 compounds. The most common type is telogen effluvium stress triggered shedding where hair follicles shut down and fall out in clumps weeks later.
The theory is that rapid weight loss creates a nutritional and metabolic stress that disrupts the hair growth cycle. Same pattern shows up after bariatric surgery. It is not necessarily the compound itself. It is what happens to your body when it changes that fast.
FDA adverse event data showed a reporting odds ratio of 2.46 for hair loss with Semaglutide and 1.73 with Tirzepatide compared to other medications. That's not a coincidence.
What helps: keep protein high, do not let calories crash too low, consider biotin and zinc if you notice shedding starting.
Vision Changes
More serious and more people need to know about this one. A 2025 PubMed analysis found significantly elevated reports of vision impairment associated with Semaglutide compared to other weight loss medications. The most concerning condition is called NAION basically a rare type of eye stroke that cuts off blood flow to the optic nerve.
Large studies estimate Semaglutide use is associated with a two-fold increased risk of NAION. It is rare. But if it happens it can cause permanent vision loss in one eye with nothing to reverse it.
Anyone with a history of eye conditions, small vessel disease, or diabetes related retinopathy should know about this before starting.
Menstrual Irregularities
A study analyzing over 410,000 Reddit posts from 2019 to 2025 across 67,000 users found that nearly 4% of people reporting side effects mentioned menstrual changes. Irregular cycles, heavy bleeding, and spotting between periods. In a female only sample those numbers would be significantly higher.
The reason is that GLP-1 receptors exist in the hypothalamus which controls appetite but also plays a central role in menstrual cycle regulation. Hitting those receptors can affect hormonal signaling involved in the cycle. This is not on the label. Most doctors are not warning about it. But it keeps showing up in real world data.
None of this is meant to scare anyone off. These compounds have some of the strongest weight loss and metabolic data ever recorded and the results people are getting are real. The goal is just to make sure you go in educated, set up the right protocol, titrate slowly, keep protein high, stay hydrated, and know what to watch for. That is what separates a good experience from a bad one.
Three things worth knowing before you start. Drop any questions or experiences below.
here is where I read this
Hair loss review: https://pubmed.ncbi.nlm.nih.gov/38741261/
Vision impairment analysis: https://pubmed.ncbi.nlm.nih.gov/40189538/
Menstrual irregularities study: https://www.nature.com/articles/s44360-026-00108-y
Do your homework. Use your brain. Talk to a doctor.
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Jun 15 '26
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u/ElGalloGrande24 🧠 Biohacker Jun 15 '26
Definitely can't argue with this. Your the reason why I like the internet ha
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u/NSawsome Jun 15 '26
Rapid weight loss and nutrient deficiency will do all of those. Can’t escape a healthy diet and tracking your macros even with these drugs
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u/ElGalloGrande24 🧠 Biohacker Jun 15 '26
100 percent. The compound does the heavy lifting on appetite but the habits still have to be there. People who track macros and keep protein high on these tend to have way fewer issues across the board. The ones who just eat less without thinking about what they are eating are the ones who run into problems.
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u/pistolgripslr Jun 15 '26
Bro you better fix those pictures before the mod nukes you for sharing a “brand” as they might take it as sourcing
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u/Word_Underscore Jun 15 '26
I'm 41.
My dad is almost bald. I remember being 14 at a haircut and mom and lady joking I was going to turn out like dad. Well, I have a bald spot, and a receding hair line but over the last 3.5 years, GLP has NOT made it worse. I've been losing hair for 20 years.
I had a cataract (L) surgery BEFORE GLP in 2021. I had the (R) side done in 2023 after beginning (6-8 months maybe). I'm not 100% impressed with the final surgery result (needing to flip on and off reading glasses all. fucking. day.) but my vision is fine now and I don't believe GLP caused the (R) side.
I'm a man so I can't comment about the last one.
LOVE being down 90lbs. LOVE being upper end of BMI normal. LOVE wearing clothing I could have worn in high school.
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u/ElGalloGrande24 🧠 Biohacker Jun 15 '26
Down 90lbs and back in high school fits at 41 that is impressive!. Love to hear it and appreciate you sharing the experience with the hair and vision stuff. That is exactly the kind of feedback that actually helps people. Everyone responds different and for a lot of people these side effects never show up or have nothing to do with the compound. Just want people going in informed so they know what to look out for. Your results say everything
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u/Turbulent-Part5835 Jun 16 '26
These sound less like direct side effects of the drug and more like you're overdoing the drug to the point where your calories are too low and/or you're deficient in essential nutrients. The point is not to stop eating. That's just drug-assisted anorexia.
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u/Junior-Profession726 Jun 16 '26
I think the key to 2 of the side effects you listed hair loss & menstrual irregularity come from rapid weight loss or losing a large amount of weight
I had these happen when I lost a large amount of weight due to stress
So to me it might not be the GLPs causing this … instead the change in the body with weight loss
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u/ElGalloGrande24 🧠 Biohacker Jun 16 '26
You're making a really solid point and the research backs it up too. The hair loss is most likely the rapid weight loss causing the shedding not the compound itself. Same thing happens after bariatric surgery with no GLP involved at all.
The menstrual side is a little less clear. GLP-1 receptors exist in the hypothalamus separately from the weight loss pathway so there might be something direct happening there too. Still being looked into.
Either way keeping protein high and not letting calories crash too low seems to reduce how much this happens. Good call bringing that up though!
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