Risankizumab is a monoclonal antibody marketed under the brand name Skrizi™. It has a large molecular weight around 146,000 Da and therefore limited oral bioavailability. Due to its pharmacokinetics it is unlikely to enter milk and in the gut, it would be rapidly metabolized by proteases in the infant’s stomach and intestines.
Mahadevan et al The Global Consensus Group consider the use of Risankizumab acceptable during breastfeeding. (Mahadevan U, Seow CH, Barnes EL, Chaparro M, Flanagan E, Friedman S, Julsgaard M, Kane S, Ng S, Torres J, Watermeyer G, Yamamoto-Furusho J, Robinson C, Fisher S, Anderson P, Gearry R, Duricova D, Dubinsky M, Long M; Global Consensus Group for Pregnancy and IBD. Global Consensus Statement on the Management of Pregnancy in Inflammatory Bowel Disease. Clin Gastroenterol Hepatol. 2025 Oct;23(11S):S1-S60. doi: 10.1016/j.cgh.2025.04.005. Epub 2025 Aug 28. PMID: 40874901.)
References
- Anderson PO. Monoclonal Antibodies During Breastfeeding. Breastfeed Med. 2021 Aug;16(8):591-593. doi: 10.1089/bfm.2021.0110. Epub 2021 May 5. PMID: 33956488.
- Stratigakis A, Paty D, Zou P, et al. A regression approach for assessing large molecular drug concentration in breast milk. Reprod Breed 2023;3:199–207. doi:10.1016/j.repbre.2023.10.003
- Hale and Krutsch Medications and Mother’s Milk online access Jan 2026
- LactMed https://www.ncbi.nlm.nih.gov/books/NBK541844/
- The PIANO study https://www.pianostudy.org/
- For more information from the NHS Specialist contact https://www.sps.nhs.uk/articles/information-resources-for-advice-on-medicines-and-breastfeeding/
For information on pharmacokinetics and how they affect the passage of drugs into breastmilk see http://s895428841.websitehome.co.uk/wp-content/uploads/2020/02/pharmacokinetics-of-drugs-passing-into-breastmilk-.pdf