Short answer: The Delestrogen Patient Information lists headache, breast pain, irregular vaginal bleeding or spotting, stomach cramps and bloating, nausea and vomiting, and hair loss as common side effects; the label gives no trial percentages for them. Delestrogen carries a boxed warning: estrogens raise the risk of endometrial cancer, and WHI found more heart attacks, strokes, breast cancer, blood clots and probable dementia with estrogen plus progestin.
What Delestrogen is approved for: Delestrogen is an estrogen injection approved to treat moderate to severe hot flashes and moderate to severe vulvar and vaginal atrophy due to menopause, low estrogen from hypogonadism, castration or primary ovarian failure, and, for palliation only, advanced androgen-dependent prostate cancer (Indications and Usage). For vaginal symptoms alone, topical vaginal products should be considered.
Source
DELESTROGEN (estradiol valerate injection, USP), prescribing information and Patient Information. Endo USA (Par Health USA). DailyMed, version published May 20, 2026. DailyMed setid e8f94df9-0692-4462-a7f0-fe019a0a3f07
ESTROGENS INCREASE THE RISK OF ENDOMETRIAL CANCER; CARDIOVASCULAR AND OTHER RISKS
Close clinical surveillance of all women taking estrogens is important, and undiagnosed persistent or recurring abnormal vaginal bleeding is checked, including endometrial sampling when indicated, to rule out cancer. There is no evidence that "natural" estrogens carry a different endometrial risk than synthetic estrogens at equivalent doses. Estrogens and progestins should not be used to prevent cardiovascular disease. The Women's Health Initiative (WHI) reported higher risks of heart attack, stroke, invasive breast cancer, pulmonary emboli and deep vein thrombosis in women 50 to 79 during 5 years of oral conjugated estrogens (CE 0.625 mg) plus medroxyprogesterone acetate (MPA 2.5 mg) compared with placebo. The WHI Memory Study reported a higher risk of probable dementia in women 65 and older during 4 years of CE plus MPA; whether this applies to younger women or to estrogen alone is unknown. Other doses, combinations and dosage forms were not studied, and in the absence of comparable data these risks should be assumed to be similar. Estrogens, with or without progestins, should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Delestrogen.
| Event | Relative risk CE/MPA vs placebo at 5.2 years (95% CI) | Placebo n = 8102 | CE/MPA n = 8506 |
|---|---|---|---|
| CHD events | 1.29 (1.02-1.63) | 30 | 37 |
| Non-fatal MI | 1.32 (1.02-1.72) | 23 | 30 |
| Invasive breast cancer | 1.26 (1.00-1.59) | 30 | 38 |
| Stroke | 1.41 (1.07-1.85) | 21 | 29 |
| Pulmonary embolism | 2.13 (1.39-3.25) | 8 | 16 |
| Deep vein thrombosis | 2.07 (1.49-2.87) | 13 | 26 |
| Colorectal cancer | 0.63 (0.43-0.92) | 16 | 10 |
| Hip fracture | 0.66 (0.45-0.98) | 15 | 10 |
WHI estrogen plus progestin substudy: 16,608 postmenopausal women aged 50 to 79 taking oral CE 0.625 mg plus MPA 2.5 mg daily or placebo, average follow-up 5.2 years. This is a study of oral pills, not of Delestrogen itself. Absolute risk is per 10,000 person-years. Invasive breast cancer includes metastatic and non-metastatic breast cancer, except in situ.
WHIMS, 4,532 women 65 and older: probable dementia in 40 women on CE/MPA (1.8%) vs 21 on placebo (0.9%), or 45 vs 22 per 10,000 women-years (relative risk 2.05).
Estrogen alone in women with a uterus raises endometrial cancer risk about 2 to 12 times over non-users, and 15 to 24 times with 5 to 10 years or more of use; the raised risk persists at least 8 to 15 years after stopping.
WHI CE/MPA: relative risk 1.58 (not statistically significant), 4.2 vs 2.7 cases per 10,000 women-years. A meta-analysis found a relative risk of 1.41 with current hormone therapy use.
A 2- to 4-fold increase in gallbladder disease needing surgery has been reported in postmenopausal women taking estrogens.
Reported with estrogen and/or progestin therapy, without frequencies: changes in vaginal bleeding, breast tenderness and enlargement, blood clots, higher blood pressure, nausea, bloating, melasma, scalp hair loss, headache, migraine, mood changes, weight changes, fluid retention, leg cramps and changes in libido.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Who should not use it. Women with undiagnosed abnormal genital bleeding, current or past breast cancer, estrogen-dependent cancer, active or past blood clots in the legs or lungs, a stroke or heart attack within about the past year, liver problems, allergy to its ingredients, or known or suspected pregnancy.
Heart attack, stroke and blood clots. Estrogen and estrogen plus progestin have been linked to heart attack, stroke, deep vein thrombosis and pulmonary embolism. Estrogens are stopped immediately if any occurs or is suspected, and if feasible at least 4 to 6 weeks before surgery linked to clots or during long immobilization.
Endometrial, breast and ovarian cancer. Unopposed estrogen raises endometrial cancer risk in women with a uterus; adding a progestin lowers the risk of endometrial hyperplasia. Estrogen plus progestin raised invasive breast cancer risk in WHI (relative risk 1.24), and observational studies show a smaller rise with estrogen alone. Yearly breast exams and monthly self-exams are advised.
Probable dementia. WHIMS found about twice the risk of probable dementia in women 65 and older on CE plus MPA. Whether this applies to younger women or estrogen alone is unknown.
High calcium. Estrogen may cause severe high calcium in women with breast cancer that has spread to bone; the drug is stopped if it occurs.
Vision problems. Blood clots in the retina have been reported. The medicine is stopped pending exam for sudden vision loss, bulging eyes, double vision or migraine, and permanently if papilledema or retinal vessel lesions are found.
Other conditions. Estrogens can raise blood pressure and triglycerides (with a risk of pancreatitis), worsen liver problems and cholestatic jaundice, raise thyroid hormone needs, cause fluid retention, and worsen endometriosis, asthma, diabetes, epilepsy, migraine, porphyria, lupus and liver hemangiomas.
From the Patient Information that comes with Delestrogen:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.