Homeopathic arnica has been recommended for many years to relieve bruising and promote healing after birth. There is little research but historical use suggests that ” homeopathic products and topical application are usually safe during breastfeeding” LactMed https://www.ncbi.nlm.nih.gov/books/NBK501828/

Homeopathic remedies (https://kellymom.com/bf/can-i-breastfeed/herbs/natural-treatments/)

“Although there is little – if any – professional literature in this field on the use of homeopathic medicine, my reading and research has led me to the conclusion that these remedies pose minimal – if any – risk to the nursing baby. Homeopathic remedies are reportedly very safe for nursing moms and babies because the remedies (by definition of homeopathy) contain only very dilute versions of the active substances.

Most experts believe that homeopathic remedies are unlikely to pose a problem for the nursing baby and mother.”

Adults and children:2 pillules every 2 hours for the first 6 doses, then 4 times daily for up to 5 days or until symptoms improve https://www.nelsonspharmacy.com/arnicare-arnica-30c-clikpak. Although Nelsons website states that you should “Consult your doctor or pharmacist before taking this product if you are pregnant or breast feeding”

Arnica cream should not be applied to broken skin.