Cyclogest is a brand name for progesterone suppositories containing micronised progesterone, a natural form of the hormone progesterone. While it is more commonly used in the context of fertility treatments and hormonal support during pregnancy, it has also been used off-label in gender-affirming care for transgender women (assigned male at birth) or individuals with androgen-dependent conditions. Progesterone therapy is often prescribed in combination with oestrogen therapy to help promote breast development and mimic the hormonal profile of cisgender women. Here are some potential unwanted/adverse/side effects of Cyclogest in the context of gender-affirming care:
| Side Effect | Description |
| Gastrointestinal discomfort | Some individuals may experience gastrointestinal discomfort, such as bloating, gas, or abdominal pain, as a side effect of using Cyclogest suppositories. |
| Vaginal discharge or irritation | Insertion of suppositories may cause vaginal discharge or irritation in some individuals. |
| Mood changes | Progesterone therapy, including Cyclogest use, may lead to mood changes, including mood swings, irritability, or changes in emotional well-being. |
| Fatigue | Fatigue or feelings of lethargy may occur as a side effect of Cyclogest therapy. |
| Headaches | Headaches are a common side effect of progesterone therapy, including Cyclogest use. These headaches may range from mild to moderate in severity. |
| Breast tenderness and enlargement | Progesterone therapy can cause breast tenderness, soreness, and enlargement due to its effects on breast tissue development. |
| Fluid retention | Progesterone therapy may lead to fluid retention, causing swelling or bloating in the hands, feet, or other parts of the body. |
| Weight changes | Some individuals may experience changes in body weight or distribution as a side effect of progesterone therapy. |
| Skin changes | Progesterone therapy may cause changes in skin texture, including increased softness or oiliness, as well as changes in pigmentation. |
| Menstrual-like bleeding | Some individuals may experience breakthrough bleeding or spotting while using Cyclogest suppositories, particularly if they have not undergone surgical removal of the gonads. |
| Rare allergic reactions | Although rare, some individuals may experience allergic reactions to Cyclogest, including rash, itching, swelling, or difficulty breathing. Immediate medical attention is necessary. |