Preparations of calendula flower are likely safe for most people when taken by mouth or applied to the skin.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Do not take calendula by mouth if you are pregnant. It is likely unsafe. There is a concern that it might cause a miscarriage. It is best to avoid topical use as well until more is known.
There is not enough reliable information about the safety of using calendula if you are breast-feeding. Stay on the safe side and avoid use.
Allergy to ragweed and related plants: Calendula may cause an allergic reaction in people who are sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many others. If you have allergies, be sure to check with your healthcare provider before taking calendula.
Surgery: Calendula might cause too much drowsiness if combined with medications used during and after surgery. Stop taking calendula at least 2 weeks prior to a scheduled surgery.