Progestins (also known as progestogens) are a group of progesterone-like hormones. It is not known exactly how progestins relieve the symptoms of endometriosis, but it is believed that they suppress the growth of the endometrial implants in some way, causing them to gradually shrink and disappear. 

Possible side effects

Progestins come in a variety of forms, each with its own advantages and disadvantages. Like all hormonal treatments, there are potential side effects with progestin; however women usually experience fewer side effects with this treatment. There are oral forms which are taken daily, or long-acting forms given through injection, implant or IUD.

Side effects may include:

• Irregular bleeding
• Breast tenderness
• Acne
• Abdominal bloating
• Fluid retention
• Mood changes / depression
• Nausea / vomiting
• Dizziness
• Tiredness
• Weight gain

Content Updated August 31, 2009