Its purpose is to manage blood sugar levels after meals, but it can also affect appetite and weight loss, hence why these medications are often used to treat obesity
PlexusDx's Precision Peptide Genetic Test reveals predispositions in appetite-regulation pathways

Other common side effects Vaginal discharge Headache Vaginal soreness or irritation Back pain Vaginal pain or discomfort Unusual vaginal bleeding Upper respiratory infection Joint pain Insomnia Stomach pain Stuffy nose Flu-like symptoms Nausea Bloating Fluid retention Breast pain Urinary tract infection Serious side effects Estring carries an FDA Boxed Warning: Estrogen-alone therapy may increase endometrial cancer risk without progestin Do not use estrogen alone to prevent dementia or cardiovascular disease Avoid combined estrogenprogestin for stroke, clot, or dementia prevention Other rare but serious effects: Heart attack (chest pain, arm pain, cold sweats, shortness of breath) Stroke (sudden weakness, severe headache, vision or speech changes) Blood clots (leg pain/swelling, lung pain, shortness of breath) Toxic shock syndrome (fever, rash, vomiting, diarrhea, muscle pain) Liver problems (abdominal pain, jaundice, nausea, fever) Severe allergic reaction (angioedema, hives, breathing difficulty) Breast lumps Increased risk of ovarian, breast, and uterine cancers High blood sugar Fibroid enlargement Thyroid level changes High blood pressure Gallbladder disease Worsening endometriosis Use in pregnancy and breastfeeding Do not use Estring if pregnantconfirm with a pregnancy test

The BMJ 2013, 347: f7110