How Does Progestin Only Birth Control Work?

By Nena Luster DNP, MBA, FNP-BC
Medically reviewed checkmarkMedically reviewed
April 1, 2022

Birth control pills (also called oral contraceptives) are one of the most effective forms of contraception available. They are highly effective and come with a relatively low number of side effects.

However, not everyone who wants to prevent themselves from getting pregnant can take them. 

Traditional birth control pills (i.e. combination birth control pills) contain a synthetic form of estrogen, which not everyone can tolerate.

For those who can’t take estrogen, there is an alternative – progestin-only birth control, otherwise known as the “mini-pill.” 

In this article, we’ll discuss what progestin-only birth control is, how you should take it, and how it works.

Progestin-only Birth Control Pills

Some people have heard about progestin-only birth control pill, but have little or no understanding of what it is, how it works, or how to take it.

Read below to find answers to these questions.

What is it?

Unlike combination birth control pills that contain both estrogen and progestin, progestin-only birth control pills contain only progestin, which is a synthetic form of a hormone called progesterone.

Progestin is a hormone released by the ovaries that helps control the menstrual cycle.

Combination birth control pills also contain progestin, but the mini-pill typically contains less progestin than traditional pills.

How to take it

Just like traditional birth control pills, progestin-only birth control pills are tablets that need to be taken at the same time every day. If you take the pill just a couple of hours late, your risk of pregnancy increases.

Progestin-only birth control pills are usually taken continuously, unlike the traditional pill.

This means when you finish one pack, you start the next pack the following day.

Why take progestin-only birth control

You may want to take progestin-only birth control if you have had negative side effects with the combination pill, like stomach aches or headaches.

Some people may not be able to take the traditional birth control pill for a variety of reasons.

How it works

Combination birth control pills contain a combination of two different hormones, progestin and estrogen. Estrogen works by stopping the release of a mature egg (ovulation).

Progestin works to cause various changes in your body, like making your cervical mucus thicker so sperm cannot go through it and making the lining of the uterus less able to support implantation and pregnancy. 

So, progestin-only pills focus on other ways of stopping fertilization aside from stopping the release of mature eggs by the ovary.

About 4 in 10 people who use this pill will still ovulate.

Who should take progestin-only birth control?

While anyone looking to prevent themselves from getting pregnant can take progestin-only birth control, it is usually used by people who cannot take the traditional pill for a variety of reasons.

These include:

  • People that are breastfeeding (estrogen in the pill can slow or stop the production of breast milk).
  • People who are over 35 years old and have a history of smoking, high blood pressure, stroke, or blood clots.
  • People who are taking medications that can interact with a medication containing estrogen.

Be sure to talk to your healthcare provider before starting progestin-only birth control pills, especially if you have liver disease, have had breast cancer, or have undergone weight-loss surgery.

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The Advantages and Disadvantages of Progestin-Only Birth Control Pills

Like with any other medication, there are advantages and disadvantages to progestin-only birth control pills.


  • More people can take it: If you are breastfeeding or have other risk factors, progestin-only pills are a better option for you.
  • It does not interact with certain medications: If you take medication that interacts negatively with estrogen, the mini-pill is safer for you to take.


  • Pregnancy risk is higher: You have a slightly higher risk of getting pregnant when taking the progestin-only birth control pill. In addition, you have an increased risk of ectopic pregnancy.
  • You must adhere to a stricter dosing schedule: It is much more important to take progestin-only pills at the same time each day.
  • Acne is the same: Unlike traditional birth control pills, progestin-only pills do not help to clear up acne.

Possible side effects

Possible side effects of taking progestin-only oral contraceptives are similar to those of combination birth control pills.

Side effects include:

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When To See a Healthcare Provider

A healthcare provider needs to prescribe the progestin-only birth control pill to you.

Once they’ve done that, they will periodically check to see how you are doing with the medication.

You should contact your healthcare provider right away if you experience any of the following problems:

  • Pain, redness, or swelling in your legs
  • Your leg feels hot to the touch
  • Chest pain
  • Problems breathing
  • Unexplained fever or chills
  • Severe abdominal pain

How K Health Can Help

If you are interested in taking the progestin-only birth control pill and would like to know more about it, talk to a healthcare provider

Did you know you can get affordable primary care with the K Health app? Download K Health to check your symptoms, explore conditions and treatments, and if needed text with a provider in minutes. K Health’s AI-powered app is based on 20 years of clinical data.

Frequently Asked Questions

Is progestin-only birth control better?
Progestin-only birth control can be used by people who are unable to use traditional (combination) birth control pills, but it is less effective at preventing pregnancy.
What are the benefits of progestin-only pills?
With progestin-only pills, you can avoid the side effects of estrogen as found in combination birth control pills.
What are the side effects of progesterone-only birth control?
Side effects of progestin-only birth control pills include nausea, breast tenderness, headache, weight gain, and weight loss.
Do you get your period on progestin-only pills?
You can still get your period on progestin-only pills, but you are more likely to have spotting or bleeding between periods.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Nena Luster DNP, MBA, FNP-BC

Nena Luster is a board certified Family Nurse Practitioner with over 14 years of experience including emergency medicine, urgent care, and family practice.