| Side Effect | Description |
| Breast tenderness and enlargement | Estrogen therapy, including Estrogel, can cause breast tenderness, soreness, and enlargement due to the promotion of breast tissue development. |
| Nausea | Some individuals may experience nausea or gastrointestinal discomfort as a side effect of oestrogen therapy, though this is usually mild and transient. |
| Headaches | Headaches are a common side effect of oestrogen therapy, including Estrogel use. These headaches may range from mild to moderate in severity. |
| Mood changes | Some individuals may experience mood swings, emotional sensitivity, or changes in emotional well-being while taking oestrogen therapy. |
| Fluid retention | Oestrogen therapy can 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 oestrogen therapy. |
| Skin changes | Oestrogen therapy may cause changes in skin texture, including increased softness or oiliness, as well as changes in pigmentation. |
| Decreased libido | A decrease in libido (sex drive) can occur as a side effect of oestrogen therapy due to changes in hormone levels. |
| Fatigue | Fatigue or feelings of lethargy may occur as a side effect of oestrogen therapy, particularly during the initial period of adjustment. |
| Decreased fertility | Oestrogen therapy can suppress sperm production and fertility in individuals assigned male at birth. It’s essential to discuss fertility preservation options with a healthcare provider if fertility preservation is desired. |
| Thromboembolic events | While less common, there is a risk of thromboembolic events (such as blood clots) associated with oestrogen therapy, particularly in individuals with other risk factors for thrombosis. |
| Rare allergic reactions | Although rare, some individuals may experience allergic reactions to Estrogel, including rash, itching, swelling, or difficulty breathing. Immediate medical attention is necessary if any signs of an allergic reaction occur. |