Could Reta plus a Low-Carb Diet Be Causing Dizzy Spells?

[BNLFL]

After another thread brought up Reddit, I went to take a look. YIKES! Anyway, someone there described feeling light headed and fainting, and a few other people chimed in too. That made me start wondering, because over the past week I've had about 2 episodes of mild light headedness, nothing serious and it clears up fast. We've seriously reduced carbs around here, no pasta, bread, blah blah. I'm still drinking somewhere between 2-4 beers (carbs) daily. I was at the doctor's office on 2/11 for blood work. All results were spot on, BP 125/70 and HR of 70bpm. The only other thing that comes to mind is that I worked my ass off digging a footer for a 25' flagpole, then placed 6-60lb bags of concrete. Because it hasn't rained here in forever, the ground was hard as hell. It beat the shit out of me.

TL;DR Could Reta mean I'm not getting enough carbs?

 

[Calm Logic]

Might not be relevant, but pseudohypoglycemia is a thing:

Google Gemini said:


SymptomTrue Hypoglycemia (Danger)Reta Pseudo-Hypo (Resetting)Feeling FaintSlow "fade out"; leads to passing out.Sudden "head rush" when standing up.Blood Glucose< 70 mg/dLNormal (80–100 mg/dL)Blood PressureUsually normal until late stages.Low / Drops suddenly (Dehydration).Heart RateRapid and weak/fluttery.Pounding / Strong thumping.VisionDarkening or "tunnel vision."Sparklers, spots, or "graying out."Immediate FixSugar (Juice/Glucose tabs).Salt, Water, & Laying Flat.

Click to expand...

Next time, consider checking BP right away (like with orthostatic hypotension). Also look at urine color to spot dehydration:

Google Gemini said:


StepActionWhat it Reveals1. Glucose CheckFinger prick or CGM check.If >75 mg/dL, it is NOT a sugar crash.2. BP CheckTest while sitting vs. standing.If it drops >20/10 mmHg, it is Orthostatic Hypotension.3. HydrationCheck urine color.Darker than "pale straw" indicates Dehydration.

Click to expand...

 

[BNLFL]

I own a blood pressure monitor for use at home and an O2 device. My readings are within the normal range. Lately I've been drinking a huge amount of water.

 

[Calm Logic]

BNLFL said:

I own a blood pressure monitor for use at home and an O2 device. My readings are within the normal range. Lately I've been drinking a huge amount of water.

If you don't replenish electrolytes at the same time, this can occasionally intensify the issue:


Google Search

lessthanhalf said:

Based on what the companies marketing GLPs say, along with chatgpt 5 in scholar/academic mode, GLP medications do not produce hypoglycaemia in people without diabetes. (When it does happen, it stems from combining them with other drugs that lower glucose.)

People frequently label symptoms like these as hypoglycaemia on their own, yet when blood sugar is actually measured in those complaining of such symptoms, genuine hypoglycaemia turns out to be quite uncommon.

One might expect reta in particular, at least early on, to be the least likely culprit given its glucagon agonism.

Genuine hypoglycaemia is a rather serious condition. It can lead to losing consciousness and is not good for brain cells. Among people who feel tired, shaky and dizzy after going without food for a stretch, which happens all the time, attaching the label hypoglycaemia to these symptoms, when measurement usually shows it is not, matters mainly because it blurs the line between something medically quite serious and something fairly harmless. Take driving: if these episodes were genuine hypoglycaemia, you should not be behind the wheel whenever there is any chance one could occur.

Every GLP medication directly lowers blood pressure, and many cut fluid intake through a direct effect on the brain's thirst centers. Add to that the fluid and electrolyte losses from early weight loss, and postural hypotension becomes more likely, which is the more probable source of these symptoms. Should it resolve when you sit or lie down, that would confirm it. What you are already doing, having a drink and something to eat, works fine as a way to handle it. Still, I would recommend putting more focus on fluid and salt/electrolyte intake, since that matters for keeping it from happening again.

 

[BNLFL]

I've just placed an order for an electrolyte powder mix.

 

[woundcarping]

BNLFL said:

After another thread brought up Reddit, I went to take a look. YIKES! Anyway, someone there described feeling light headed and fainting, and a few other people chimed in too. That made me start wondering, because over the past week I've had about 2 episodes of mild light headedness, nothing serious and it clears up fast. We've seriously reduced carbs around here, no pasta, bread, blah blah. I'm still drinking somewhere between 2-4 beers (carbs) daily. I was at the doctor's office on 2/11 for blood work. All results were spot on, BP 125/70 and HR of 70bpm. The only other thing that comes to mind is that I worked my ass off digging a footer for a 25' flagpole, then placed 6-60lb bags of concrete. Because it hasn't rained here in forever, the ground was hard as hell. It beat the shit out of me.

TL;DR Could Reta mean I'm not getting enough carbs?

When on Reta and physically active, carbs help prevent blood sugar from dropping too low (hypoglycemia). A few instances left me feeling unwell, and fast-acting carbs resolved it.

Stories from others about comparable situations, even fainting, show up fairly often among the stronger adverse effects beyond merely stomach problems.

Just wondering, why are you removing carbs?

 

[tubby]

I mean, you're putting your metabolism through the wringer here.

To start, you cut off all the carbs it normally receives daily, and that alone takes anywhere from a few days up to a week before it adjusts and gets comfortable doing without them. Then you deceive it with that fake GLP-1 signal continuously sent to your brain yelling "I just ate," so it reasonably figures more carbs are being emptied into your stomach, which (since they don't exist) it has no way to absorb. It also releases a bit of extra insulin to handle those phantom carbs.

So don't act shocked when it treats you the same way right back for a while.

 

[BNLFL]

woundcarping said:

BNLFL said:

After another thread brought up Reddit, I went to take a look. YIKES! Anyway, someone there described feeling light headed and fainting, and a few other people chimed in too. That made me start wondering, because over the past week I've had about 2 episodes of mild light headedness, nothing serious and it clears up fast. We've seriously reduced carbs around here, no pasta, bread, blah blah. I'm still drinking somewhere between 2-4 beers (carbs) daily. I was at the doctor's office on 2/11 for blood work. All results were spot on, BP 125/70 and HR of 70bpm. The only other thing that comes to mind is that I worked my ass off digging a footer for a 25' flagpole, then placed 6-60lb bags of concrete. Because it hasn't rained here in forever, the ground was hard as hell. It beat the shit out of me.

TL;DR Could Reta mean I'm not getting enough carbs?

When on Reta and physically active, carbs help prevent blood sugar from dropping too low (hypoglycemia). A few instances left me feeling unwell, and fast-acting carbs resolved it.

Stories from others about comparable situations, even fainting, show up fairly often among the stronger adverse effects beyond merely stomach problems.

Just wondering, why are you removing carbs?

Yeah, I went way too hard on myself and overdid it. I'm 66, not 45. About the carbs, the weight loss, and scaling way back—it's not a complete cut. These days I don't usually take on that much intense labor; I just handle the payments.

 

[BNLFL]

tubby said:

I mean, you're putting your metabolism through the wringer here.

To start, you cut off all the carbs it normally receives daily, and that alone takes anywhere from a few days up to a week before it adjusts and gets comfortable doing without them. Then you deceive it with that fake GLP-1 signal continuously sent to your brain yelling "I just ate," so it reasonably figures more carbs are being emptied into your stomach, which (since they don't exist) it has no way to absorb. It also releases a bit of extra insulin to handle those phantom carbs.

So don't act shocked when it treats you the same way right back for a while.

Thanks, I really do appreciate that. To be clear, I'm still taking in decent carbs — I've just dropped the white stuff. On top of that, no more ice cream, cookies, or sweets. The reason I kicked off this thread was mostly because of what I came across on Reddit, plus the fact that I pushed myself too hard last week.

 

[woundcarping]

Both occasions where I felt off happened prior to physical effort, though by then I hadn't consumed much food that day.

While on Reta, the daily minimum macros I aim for are 150g protein, 100g carbs, and 50 grams of fat, staying under 2200 calories.

Yesterday, the bulk of my carbs came from French fries, a soft serve ice cream cone before lifting, and a blow pop afterward.

 

[Calm Logic]

woundcarping said:

BNLFL said:

After another thread brought up Reddit, I went to take a look. YIKES! Anyway, someone there described feeling light headed and fainting, and a few other people chimed in too. That made me start wondering, because over the past week I've had about 2 episodes of mild light headedness, nothing serious and it clears up fast. We've seriously reduced carbs around here, no pasta, bread, blah blah. I'm still drinking somewhere between 2-4 beers (carbs) daily. I was at the doctor's office on 2/11 for blood work. All results were spot on, BP 125/70 and HR of 70bpm. The only other thing that comes to mind is that I worked my ass off digging a footer for a 25' flagpole, then placed 6-60lb bags of concrete. Because it hasn't rained here in forever, the ground was hard as hell. It beat the shit out of me.

TL;DR Could Reta mean I'm not getting enough carbs?

When on Reta and physically active, carbs help prevent blood sugar from dropping too low (hypoglycemia). A few instances left me feeling unwell, and fast-acting carbs resolved it.

Stories from others about comparable situations, even fainting, show up fairly often among the stronger adverse effects beyond merely stomach problems.

Just wondering, why are you removing carbs?

On top of that, there's the everyday tiredness that comes with tirz/reta when you're cutting back on carbs and calories—plus other GLP-related factors that might wear you down—even when you're completely inactive, which can make the GLP brain fog worse:

Google Gemini said:


FactorMechanism of Fatigue/FogAdaptation / ResolutionNutritional GapLower carbs/calories mean less immediate glycogen for the brain.Manual Adjustment: Does not "adapt" away; requires intentional nutrient timing or small snacks to fuel the brain.Metabolic ShiftForcing the body to burn fat (ketone production) is "harder" work than burning sugar.4–8 Weeks: Mitochondria become more efficient at fat oxidation ("fat-adapted"), making the process feel less taxing.InactivityLack of movement reduces the "pressor" effect that clears brain metabolic byproducts.Behavioral: Fog persists as long as you stay sedentary; "breaking the seal" with light movement is usually the only fix.CNS SignalingDirect effect on the hindbrain reduces dopamine "drive" and alertness.6–12 Weeks: Central Nervous System (CNS) desensitization. The "muted" feeling usually lifts once you stop titrating up.

Click to expand...

 

[BNLFL]

This is exactly the reason I signed up for this community. Information like this isn't something you come across on the internet.

 

[GLP1Pharmacist]

My best guess: blood sugar is dropping too low. The body might prioritize burning alcohol rather than keeping glucose at a sufficient level. When my RS has 3 drinks, roughly 2-3 hours afterward there’s a reliable plunge in blood sugar that goes far too low. Even 2 drinks can make a big difference, so it’s either 1 or none. Check blood sugar...

 

[woundcarping]

Calm Logic said:

woundcarping said:

BNLFL said:

After another thread brought up Reddit, I went to take a look. YIKES! Anyway, someone there described feeling light headed and fainting, and a few other people chimed in too. That made me start wondering, because over the past week I've had about 2 episodes of mild light headedness, nothing serious and it clears up fast. We've seriously reduced carbs around here, no pasta, bread, blah blah. I'm still drinking somewhere between 2-4 beers (carbs) daily. I was at the doctor's office on 2/11 for blood work. All results were spot on, BP 125/70 and HR of 70bpm. The only other thing that comes to mind is that I worked my ass off digging a footer for a 25' flagpole, then placed 6-60lb bags of concrete. Because it hasn't rained here in forever, the ground was hard as hell. It beat the shit out of me.

TL;DR Could Reta mean I'm not getting enough carbs?

When on Reta and physically active, carbs help prevent blood sugar from dropping too low (hypoglycemia). A few instances left me feeling unwell, and fast-acting carbs resolved it.

Stories from others about comparable situations, even fainting, show up fairly often among the stronger adverse effects beyond merely stomach problems.

Just wondering, why are you removing carbs?

On top of that, there's the everyday tiredness that comes with tirz/reta when you're cutting back on carbs and calories—plus other GLP-related factors that might wear you down—even when you're completely inactive, which can make the GLP brain fog worse:

Google Gemini said:


FactorMechanism of Fatigue/FogAdaptation / ResolutionNutritional GapLower carbs/calories mean less immediate glycogen for the brain.Manual Adjustment: Does not "adapt" away; requires intentional nutrient timing or small snacks to fuel the brain.Metabolic ShiftForcing the body to burn fat (ketone production) is "harder" work than burning sugar.4–8 Weeks: Mitochondria become more efficient at fat oxidation ("fat-adapted"), making the process feel less taxing.InactivityLack of movement reduces the "pressor" effect that clears brain metabolic byproducts.Behavioral: Fog persists as long as you stay sedentary; "breaking the seal" with light movement is usually the only fix.CNS SignalingDirect effect on the hindbrain reduces dopamine "drive" and alertness.6–12 Weeks: Central Nervous System (CNS) desensitization. The "muted" feeling usually lifts once you stop titrating up.

Click to expand...

Up to this point, I’ve been lucky enough that my energy has been at least decent, or even better, from what I can recall. Part of that luck likely comes from beginning TRT 5 weeks into Tirz. I began logging calories and macros on the same day as TRT, and since then my carbs have averaged roughly 130g per day, with the lowest week at 113g. I’m down 13lb since starting TRT, and 28lb overall with GLP since 12/10/25.

From January onward, the only exercise days I skipped were 3 days spent recovering from lifting DOMS (my first leg day got a little out of hand), plus 1 day of travel and laziness.

 

[tubby]

BNLFL said:

tubby said:

I mean, you're putting your metabolism through the wringer here.

To start, you cut off all the carbs it normally receives daily, and that alone takes anywhere from a few days up to a week before it adjusts and gets comfortable doing without them. Then you deceive it with that fake GLP-1 signal continuously sent to your brain yelling "I just ate," so it reasonably figures more carbs are being emptied into your stomach, which (since they don't exist) it has no way to absorb. It also releases a bit of extra insulin to handle those phantom carbs.

So don't act shocked when it treats you the same way right back for a while.

Thanks, I really do appreciate that. To be clear, I'm still taking in decent carbs — I've just dropped the white stuff. On top of that, no more ice cream, cookies, or sweets. The reason I kicked off this thread was mostly because of what I came across on Reddit, plus the fact that I pushed myself too hard last week.

Mostly I'm just teasing you a bit, but the truth is that when you make major changes, your body requires time to adjust, and stacking 2 of them at once will put a bit more strain on it. Doing low-carb while on reta isn't a problem at all, and some would even say it's the better route, in that it helps break the pattern of consuming the more addictive processed foods you might have had in your diet previously.

 

[tubby]

GLP1Pharmacist said:

My best guess: blood sugar is dropping too low. The body might prioritize burning alcohol rather than keeping glucose at a sufficient level. When my RS has 3 drinks, roughly 2-3 hours afterward there’s a reliable plunge in blood sugar that goes far too low. Even 2 drinks can make a big difference, so it’s either 1 or none. Check blood sugar...

That's a fair observation I overlooked when I first went through OP. "2-4 beers a day" might refer to drinking them throughout the day, right when he's experiencing this issue, rather than in the evening, which is what I figured on my initial pass.

With alcohol and a GLP both working to lower average blood sugar, the low points do end up going a bit deeper whenever you reach them.

 

[BNLFL]

Yeah, I've been thinking about the beer for a while now—it just makes me feel full and I don't really get much pleasure from it anymore. It wasn't a problem before, but it tracks that things changed once I began this at the start of Feb. Like I said, I'm grateful for everyone's feedback.

 

[Calm Logic]

BNLFL said:

Yeah, I've been thinking about the beer for a while now—it just makes me feel full and I don't really get much pleasure from it anymore. It wasn't a problem before, but it tracks that things changed once I began this at the start of Feb. Like I said, I'm grateful for everyone's feedback.

Yes, the current line is that "there is no healthy amount of alcohol." Back when it was believed to benefit the heart, I would occasionally enjoy a glass of wine with a meal (the buzz being an extra perk), but these days I mostly just have plain water or hot black coffee.

So, @BNLFL, have you given the zero-alcohol beers a shot? They're actually quite decent. As for catching a buzz, marijuana gummies once struck me as nearly healthy, yet a small study (CANDIDE study, 2025) indicates they harm the endothelium.

A liver specialist on Reddit claims the top "supplement" for the liver is black coffee. NAC is a solid supplement overall, but particularly for the liver:

Gemini said:


If you are using NAC specifically to protect your liver from alcohol, timing is everything:

Take it BEFORE drinking: Taking NAC an hour or two before alcohol can help prime the liver and prevent damage.

Avoid it DURING/AFTER drinking: Some studies suggest that taking NAC after you’ve already started drinking (or while hungover) might actually increase liver stress or toxicity. It’s best used as a "pre-game" preventative rather than a "morning-after" cure.

Click to expand...

 

[tubby]

Calm Logic said:

BNLFL said:

Yeah, I've been thinking about the beer for a while now—it just makes me feel full and I don't really get much pleasure from it anymore. It wasn't a problem before, but it tracks that things changed once I began this at the start of Feb. Like I said, I'm grateful for everyone's feedback.

Yes, the current line is that "there is no healthy amount of alcohol." Back when it was believed to benefit the heart, I would occasionally enjoy a glass of wine with a meal (the buzz being an extra perk), but these days I mostly just have plain water or hot black coffee.

So, @BNLFL, have you given the zero-alcohol beers a shot? They're actually quite decent. As for catching a buzz, marijuana gummies once struck me as nearly healthy, yet a small study (CANDIDE study, 2025) indicates they harm the endothelium.

A liver specialist on Reddit claims the top "supplement" for the liver is black coffee. NAC is a solid supplement overall, but particularly for the liver:

Gemini said:


If you are using NAC specifically to protect your liver from alcohol, timing is everything:

Take it BEFORE drinking: Taking NAC an hour or two before alcohol can help prime the liver and prevent damage.

Avoid it DURING/AFTER drinking: Some studies suggest that taking NAC after you’ve already started drinking (or while hungover) might actually increase liver stress or toxicity. It’s best used as a "pre-game" preventative rather than a "morning-after" cure.

Click to expand...

I want to put it out there that I'm quite doubtful about those alcohol studies claiming "no healthy amount." Not because I've examined them in great depth, but because observational data simply can't support such a definitive conclusion. So unless China locked people in rooms and made some drink while others didn't (the only way to truly settle this) and I somehow missed it, I'm going to assume the researchers are leaning on flimsy observational data and presenting it as far more conclusive than it is.

That said, I probably only have alcohol 3 or 4 times a year (it just isn't usually interesting to me) so I have no personal stake in the outcome other than calling out bullshit results when I smell them.

 

[jungletech]

For me, cutting carbs is a real struggle, and it leaves my energy levels tanked. My thinking is that I have to pick one path: strict keto or a middle-ground carb intake.