In his TikTok, Sid claims, “You’re supposed to apply deodorant at night,” and then cites an article by Garnier that says, “The most effective time of day to apply deodorant is at night before going to bed, and it is especially important to apply your antiperspirant at night. Your body temperature is lower and your underarms dryer at this time, so the deodorant will have a better chance to work on your skin.”

Clearly, Sid struck a nerve, because his TikTok has been viewed more than 3.8 million times and received 582k likes and 10.5k comments — many of which express shock and others that reveal they do actually apply deodorant at night.

In order to get to the bottom of this, BuzzFeed spoke with Dr. Dustin Portela, a board-certified dermatologist, who explained that deodorant is primarily used to mask odor. Therefore, it's unnecessary to use before bed. However, it may be beneficial to apply antiperspirant, which is used to prevent sweating, at nighttime — particularly if you deal with excess sweating.

If you are someone who deals with excess sweating, like hyperhidrosis, Dr. Pertola noted, “Those [who naturally sweat a lot] will benefit from using their antiperspirant at nighttime because our sweat glands are the least active while we’re sleeping.”

If you are planning to apply antiperspirant before bed, Dr. Portela recommended cleaning your underarms beforehand and making sure they're completely dry before applying antiperspirant.

So, turns out, Sid was onto something. BuzzFeed reached out to Sid, who had heard about the claim from someone in his DMs. When asked about his own experience, Sid said, “I tried it for a little, but it’s a very hard habit to break if you’ve been doing it in the morning the whole time.” He added that he wasn’t sure he noticed a huge difference when applying deodorant at night.

As for why Sid decided to share this advice, he features a series on TikTok with videos on tips and lessons that he wishes he'd known before he turned 30. He explained, “I wanted to make this because it’s the opposite of what most of us know and do. A lot of us do things every day that we’ve just done because that’s what we’ve thought, so this was a chance to tell people that, actually, we’re wrong.”
