Funny thing though is that birth control doesn’t “regulate periods.” The “periods” one has on birth control pills are not real periods. They are just withdrawal bleeding from a week of pills without any hormones. That week was built into the system for the psychological well-being of the women taking the pills. The doctors who invented the pill thought that the total absence of periodic bleeding would weigh too heavily on women, making them think they might be pregnant or that something was wrong with them. After all, when not pregnant or breastfeeding, that monthly period is one signal that things are working right.
Prescribing birth control pills to “regulate periods” does not help the woman’s reproductive or endocrine functions in any way. It’s purely a psychological tactic, making everything LOOK normal and masking whatever problem is making things operate abnormally.
I would encourage the woman in question to get a second opinion, find out what is actually causing irregularity in her cycles, and then go forward with that information. Doing something substantive is alwys preferable to window-dressing.