Jessica Simpson has sparked an Instagram debate.

Earlier this week, the singer and fashion designer, 38, posted a photo to Instagram of what appeared to be more than 5 ounces of breast milk.

“This is what success feels like,” Simpson, who gave birth to her and husband Eric Johnson’s third child, Birdie Mae Johnson, on March 19, wrote alongside the image.

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Actresses Hilary Duff and Melissa Joan Hart were among those commending Simpson on the small victory, as were many other fans.

But some social media users seemed to take offense to Simpson’s photo, saying some mothers are forced to choose formula because they are unable to breastfeed.

“Breastfeeding is great but for all the moms out there that can’t breastfeed or simply are ‘done’ due to choice, formula is also the best you can do for your child,” wrote one person in response.

"What a great way to make others who can’t [breastfeed] feel like failures. Think before you post…” a second commented.

Many fans quickly jumped to Simpson's defense, writing the star shouldn’t feel guilty for sharing the image.

“No one was or is formula shaming. No one,” wrote one fan.

"Yes, mama! And don't let anyone rain on your parade, you should be proud, and that is a successful pump. You're not putting anyone down by saying that, even if others now try to put you down for it,” another commented.

"It's unbelievable how many of you women are shaming her for feeding her kid," said a third. "She's not formula bashing or anything close to it. Pumping is HARD. It's her personal victory and she's allowed to be proud of it."

Others seemed to express envy of Simpson’s ability to fill the bottle, with one person writing the photo was “the only thing I’ve legit ever seen on social media that’s made me jealous. What I wouldn’t have given for such a successful pump!”

“I wish I could pump that much!” wrote another. “Currently breastfeeding my 6-week-old and the max I’ve ever pumped is 4 ounces (that’s both sides combined.)”

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“Is it nuts that I’m jealous? I wish I could pump this much!” wrote one woman.

Some mothers also took the opportunity to share why they were unable to breastfeed their child.

“I became depressed because I had envisioned breastfeeding my son, but due to a medical condition, my dream got crushed. I’d cry over only being able to pump just a little bit. I felt like a failure from so many different aspects and from many judgmental people. Being able to breastfeed is a beautiful gift and I’m glad you are able to share that with your baby,” one user wrote, in part.