Henshaw said that filters "take away what makes us unique" and urged her followers not to "compare yourself to the filters, you are so much more".
The health influencer stressed that she wasn't judging people who used filters for "fun" but wanted to make it clear that we shouldn't judge our appearances based off "impossible beauty standards".
Henshaw's post, which has been viewed more than 132,000 times, was praised by her followers as the "best post I've seen for so long".
"This makes my heart truly ache. I didn't even know filters like this existed. Thank you for sharing and bringing awareness. Being ourselves is simply enough. We don't need layers," one person wrote.
"That's actually insane! Not to mention quite scary," another commented.
Others thanked Henshaw for sharing her face without filters and said they preferred her natural appearance anyway.
"Such an important reminder! Skin has texture!" one wrote.
"Confirms that I love your real face better," another commented.
Henshaw isn't the first public figure to call filters out, with other celebrities previously slamming the tool for altering facial features.
Earlier this year former Little Mix singer Jesy Nelson urged her young followers not to use them, pointing out that while they made her look "fresher" they also gave her a "tiny nose and huge lips".
"I don't understand why Instagram feels the need to squash your nose and make it really skinny. What's wrong with a standard nose?" she said in an Instagram story.
"I'm so confused why whoever makes these filters think that is what beauty is?"
Pop star Halsey also spoke out against filters, telling Byrdie: "I'm exhausted with this industry of Instagram filters.
"It's gotta be damaging to your brain to constantly be looking at yourself through an altered lens and being disappointed with what your face actually looks like."
The overuse of filters on Instagram has even prompted the UK to take action against them in February.
The Advertising Standards Authority has now banned their use in advertisements on the app if they enhance the effect of a product.