I am considering starting birth control, but my friend told me it can lower supply. My daughter is 5 months old, and breastfeeding is going well so I’m nervous, but not ready for another baby. Will birth control ruin my milk supply?
Using a hormonal birth control method such as “the pill” can possibly lower your milk supply. It seems to be more of a problem if it’s started within the first few weeks after birth. There is a progestin-only pill called the “mini-pill” that is better to use while breastfeeding.
There are non-hormonal options too, such as a non-hormonal IUD, condoms, diaphragms, etc. that do not affect breastfeeding.
If your baby is less than six months old, you can use the Lactational Amenorrhea Method (LAM). You need to not have your period yet. And you need to be only breastfeeding around the clock with no formula or solid foods. This is a topic you may want to discuss with your healthcare provider.
It's possible for your menstrual cycle to have a temporary effect on your milk supply and your baby. Click here for more information.
SOURCE: https://www.llli.org/breastfeeding-info/birth-control/