Lots of TikTok stars are quite young. But Harper Zilmers looks even younger than usual.
So, how old is she?
Well, the influencer was born on March 20, 2009. That means that Harper Zilmer’s age at the time of writing this article is 16 years!
Why might fans think she’s younger than she is? Is she much younger than her sister, Reese? Read on to find out!
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The Reason Harper Zilmer Looks Younger Than She Is
On an episode of the LOL Podcast, Harper Zilmer spoke up about her health issues (both mental and hormonal).
The young influencer has a rare condition that affects her growth hormone production, which has kept her body petite so far. In fact, Zilmer says that she was “in the body of a six-year-old” when she was 12 years old.
For reference, she was around 4’2” at the time. She also used to weigh a mere 64 pounds as an 8th grader. In the 4th grade, she was only 34 pounds and about 3’6” tall. That being said, she is taking growth hormones now to help with her condition, and she’s grown a bit since then.

Image source: Instagram
She’s open about the whole thing, too. You might even come across videos of her using growth hormone injections on TikTok. She also made it clear that she’s aware she’s short for her age, but she loves being short.
Harper vs. Reese Zilmer: The Age Gap Between the Sisters
If you follow Harper Zilmer on TikTok, you’ve likely seen videos that she did with her sister Reese. Now, it’s obvious that Reese is the bigger sister, but how old is she exactly?
Reese was born in December 2006, which means she’s 18. Of course, she celebrated her big b-day in style!

Image source: Instagram
Final Thoughts
To recap, Harper Zilmer is an almost 16-year-old high schooler as of March 20, 2025.
Yes, her body is smaller than others her age, but she made it clear she isn’t insecure about it. And why would she? She’s perfect just the way she is!
Featured image source: Google