Ren Shen yang ying fomula and nursing

The vast majority of formulas are technically safe during breastfeeding so long as they are properly prescribed (i.e. for your Chinese Medicine diagnosis, not chosen for symptoms).

For my patients, I generally recommend that they take herbal formulas right after breastfeeding or pumping - this way they are essentially gone by the next feeding.

The more important consideration in my mind is that you are taking whatever formula, in this case ren shen yang rong wan, for the right reasons. If you are then there is little to worry about. Ren Shen Yang Rong Wan is generally used for spleen qi and/or blood deficiency. This is often a very appropriate formula post-partum. Another formula that is commonly use d post-partum is ba zhen wan. Both of which will generally aid milk supply as they are tonifying the weakness in the body.

Ultimately, however, your practitioner is the person to ask this question to as they are most familiar with your medical history and current signs and symptoms.