Shereene IdrissBoard Certified Derm, Founder and Chief Nerd

No one ever tells you this about Botox…And yes, this is different than exercise bc it’s been 2mo

25 Apr 2026 · 1 min

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1:18

In this YouTube clip, cosmetic dermatologist Dr. Shereene Idriss answers a viewer’s concern about redness (blanching) that appears after intense exercise following Botox injections. She explains that the issue stems from injections placed too superficially in the skin rather than deep into the muscle. Superficial Botox blocks acetylcholine, preventing vasodilation in the treated area, so blood vessels do not flush and the skin appears less red, a phenomenon she calls blanching. While this depth is insufficient for wrinkle reduction, it can be beneficial for treating rosacea by reducing facial redness. Dr. Idriss clarifies that the effect is unrelated to post‑procedure exercise restrictions and emphasizes the distinction between superficial and deep injection techniques, noting the potential therapeutic use of superficial Botox for rosacea patients.

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Um, why did no one ever tell me before I got anti-aging injections, or whatever you call it, um, on this app, that if you go to a really hard cycle class, you go to a Pilates class, the injection points won't go red? I look fucked.
Because someone effed up your Botox and you got injected way too superficially. But that may not be a bad thing if you have rosacea. Stick with me till the end, I'll explain why. What you're seeing is called blanching, and your blood Vessels when you flush tend to dilate and you get really red. But with Botox, Botox blocks acetylcholine, which blocks your muscles from contracting, but also your blood vessels from vasodilating. So wherever you had Botox injected, those blood vessels don't open up as much and you do not flush in those areas. And this has nothing to do with not working out for 24 hours. This happens when Botox is injected too superficially on the surface of the skin and not deeper in your muscle. But it's something I would do for patients with rosacea who cannot necessarily afford multiple laser treatments or are looking for a quicker fix. Notice how superficial I'm injecting over here. So Botox will help your effing wrinkles if you go deep enough, but in her case, they were way too superficial and all she got was redness reduction. Let me know if you have questions below.