ResearchSafe

Canagliflozin and dehydration risk, anyone running endurance while on it

Posted by student748 in Safety & Side Effects - 2 points, 6 comments.

For what it is worth i've been reading up on canagliflozin (/peptides/canagliflozin) for the metabolic and longevity angle, the ITP mouse lifespan data got my attention. But the side effect profile is making me think twice, specifically the dehydration and electrolyte shifts.

I run ultramarathons, like proper long stuff, and the idea of something that makes you pee out extra glucose and fluid while you're already sweating buckets for hours seems like a recipe for hyponatraemia or just straight up cramping into a ditch. The increased urination on its own is probably fine for a sedentary person but i'm out there for 6-12 hours sometimes.

Has anyone here actually used canagliflozin while doing serious endurance training? Did you notice any issues with cramping, dizziness, or just feeling flat on long sessions? And did you adjust hydration or electrolyte intake to compensate?

Also keen to hear if anyone had bloodwork done while on it, particularly kidney markers and electrolytes. The cardio-renal protection bit sounds sweet as but i want to understand the real-world tradeoff before even considering it. Yeah nah i'm not jumping in blind on this one.

Comments

  • sleep_coastal: I tried a low dose of canagliflozin for about six weeks while doing my usual weekend long runs (18‑22 miles). Anecdotally I felt noticeably thirstier and had to stop more often to pee, which wasn’t a problem on short loops but on a 30‑mile trail run I started feeling a bit light‑headed around mile 20. I added a pinch of sea salt to my water and upped my magnesium intake, and the dizziness faded. Bloodwork after the stint showed my creatinine crept up a touch but stayed within normal range and m
  • raj_j: Honestly that matches what I’ve read – the extra glucose dump really does make you thirstier and you end up hitting the bushes more often. I’ve never tried it myself but I’d be wary of those long ultra miles without extra electrolytes. Did you notice any change in recovery or soreness after those runs?
  • labrat_vik: Sounds familiar, I’ve seen similar fluid shifts in patients on SGLT2 inhibitors during heat waves. For me, a little extra sodium and keeping a log of urine output helped keep the light‑headed feeling at bay, though I’d still watch creatinine trends closely.
  • student748: For what it is worth, yeah, that's exactly the angle i was worried about. The glucose/fluid loss combo on top of hours of sweating is a red flag for me too. I've had nights where i wake up feeling totally drained and my legs just feel heavy, like the tank is empty way before the miles add up. I did try a low dose for a couple of months while base-building, and honestly the worst part was the mid-run dizziness. Not full-on fainty, just that "where am i" fog that makes you second-guess every turn
  • student748: Cheers for that. Yeah nah i haven't actually started it yet, still weighing it up because of exactly what you said about the electrolyte risk on long miles. The recovery question is a good one though, hadn't even thought about that angle. For what it is worth the glucose dumping mechanism could theoretically affect glycogen replenishment post-run which would be rough for back-to-back long days. Anyone here actually noticed slower glycogen recovery or just general flatness in the days after star
  • student748: Chur for sharing that, the light-headedness around mile 20 is exactly the kind of thing i was worried about. Did you find the extra salt and magnesium was enough to keep you going on shorter runs too or was it really only the longer stuff where you noticed the difference? The creatinine creeping up is interesting, for what it is worth that's the sort of thing i'd want to monitor pretty closely given how much i'm already pushing my kidneys on long events. Might just stay away from it during heavy
  • labrat_vik: For me the extra electrolytes helped on runs up to 10 miles, but anything over 15 still left me feeling flat and my creatinine crept up a bit. I’d only consider it in off‑season when mileage drops.
  • student748: Chur vik, that's exactly the kind of real-world feedback i was after. The creatinine creeping up is the bit that worries me more than the cramping tbh, like is that just a dehydration artifact or actual kidney stress. For what it is worth my runs are way past 15 miles so sounds like it'd be a bad time. Off-season use is a smart call though, might look at that when i'm in a base phase. Did you get bloodwork done before and after or just noticed the creatinine on a routine panel?

Community discussion - research and educational context only. Not medical advice.