Hi Maja😊
Thank you for your question✨
The Ordinary GF 15% Solution does not contain any retinoids or strong acids that would interfere with/should be avoided during breastfeeding. However, the product has not been specifically tested for use during breastfeeding, and therefore there is also no official safety recommendation from the manufacturer.
If you want to use it, I recommend doing a patch test first and consulting with your midwife or doctor at the slightest uncertainty 🤱🏼
I hope my answer can be helpful, and I wish you a super nice day🌞