Prometrium (micronized progesterone) is a bioidentical hormone primarily prescribed for two FDA-approved purposes: to prevent endometrial hyperplasia (abnormal thickening of the uterine lining) in postmenopausal women using systemic estrogen therapy, and to treat secondary amenorrhea (absence of menstrual periods in women who previously menstruated). By supplying progesterone, Prometrium counterbalances estrogen’s proliferative effect on the endometrium, supporting a more physiological cycle and reducing the risk of estrogen-only therapy on the uterus.
Clinically, Prometrium is also used off-label in reproductive endocrinology to support the luteal phase in assisted reproductive technology (ART) or suspected luteal phase deficiency, and sometimes in perimenopause to improve sleep and mitigate vasomotor symptoms. Its bioidentical structure can be better tolerated by some patients compared to certain synthetic progestins, with potential differences in lipid profile, mood effects, and breast tenderness—though individual responses vary and must be closely monitored.
Because it can cause sedation, many patients take Prometrium at bedtime. When used as part of menopausal hormone therapy (HRT), it is often cycled (for example, 12–14 days of each 28-day cycle) or taken continuously alongside estrogen, depending on bleeding patterns, symptom control, and clinician preference. Prometrium capsules are designed for oral use; however, some specialists employ them vaginally off-label for targeted endometrial exposure in fertility care—always under explicit medical guidance.
Your exact dose, timing, and regimen should be individualized by your clinician, who will consider age, uterus status, concurrent estrogen therapy, medical history, and treatment goals. Typical adult regimens include: Endometrial protection during estrogen therapy: 200 mg by mouth at bedtime for 12 days of a 28-day cycle (cyclic regimen). Some clinicians use 100 mg nightly continuously; bleeding patterns and endometrial health guide adjustments. Secondary amenorrhea: common regimens include 400 mg by mouth at bedtime for 10 days or 200 mg twice daily for 10 days, after which a withdrawal bleed typically occurs within a week of completion.
Fertility and luteal support (off-label): doses vary widely (for example, 200–300 mg daily in divided doses by mouth or vaginal capsule administration under specialist care). For IVF, vaginal progesterone is often preferred, but some clinicians incorporate oral micronized progesterone for additional support. Do not change routes (oral vs. vaginal) or dosing without explicit instruction.
Administration tips: Take Prometrium at the same time daily, typically at bedtime to minimize dizziness or drowsiness. Consistency matters. Food can alter absorption of micronized progesterone; follow your prescriber’s or product label’s guidance on with/without food. Swallow capsules whole with water. Avoid alcohol or other sedatives near dosing until you know how you respond. If you experience bothersome daytime sedation, ask your clinician about adjusting timing or dose.
Safety begins with a thorough assessment. Share your complete medical history, including clotting disorders, thromboembolic events, migraines, liver disease, breast or gynecologic cancers, depression, and any history of abnormal uterine bleeding. Tell your clinician if you smoke, have obesity, diabetes, uncontrolled hypertension, or a family history of hormone-sensitive cancers—these may alter risk-benefit considerations, especially when progesterone is used with systemic estrogen.
Prometrium commonly causes drowsiness, dizziness, or a “groggy” feeling the next morning, particularly at higher doses. Until you know your response, do not drive or operate machinery after taking it. Alcohol, cannabis, benzodiazepines, antihistamines, and sleep medicines can intensify sedation. Report new or worsening headaches, visual changes, right upper abdominal pain, sudden leg swelling, chest pain, or neurological deficits immediately, as these can signal rare but serious adverse events.
Irregular bleeding can occur during the first 1–3 months as your body adjusts. Unexpected heavy bleeding, postmenopausal bleeding, or bleeding after sexual activity warrants evaluation to rule out structural causes. If you are using Prometrium for amenorrhea or cycle regulation, your clinician may track your cycles, perform pelvic ultrasound, or check labs (thyroid, prolactin, pregnancy test) to optimize care and ensure no underlying pathology is missed.
Do not use Prometrium if you have: Known hypersensitivity to progesterone or any capsule component; Prometrium capsules contain peanut oil, so a peanut allergy is a strict contraindication. Active or history of thromboembolic disorders (deep vein thrombosis, pulmonary embolism) or thromboembolic stroke, particularly in the context of combined estrogen-progestin therapy. Severe liver impairment or liver disease, including cholestatic jaundice or hepatic tumors.
Other contraindications include: Undiagnosed abnormal genital bleeding until evaluated. Known or suspected breast cancer or estrogen/progesterone-sensitive neoplasia without specialist oversight. Pregnancy when not specifically indicated by your fertility specialist (routine endometrial protection in pregnancy is not appropriate). Always confirm with your clinician; in reproductive medicine, progesterone is frequently used under closely monitored protocols, which can alter typical rules for pregnancy use.
Common side effects: Drowsiness, dizziness, fatigue, or “hangover” sensation; breast tenderness; bloating; mild nausea; headache; mood changes or irritability; and spotting or breakthrough bleeding. Many of these improve after the first few cycles or with timing adjustments (e.g., strictly at bedtime).
Less common side effects: Fluid retention, acne or oily skin, changes in libido, constipation, or diarrhea. Some patients report improved sleep quality, while others may feel groggy—highlighting individual variability. If sedation is excessive, discuss a dose or schedule adjustment with your clinician.
Serious adverse events (seek urgent care): Sudden chest pain, shortness of breath, coughing blood; unilateral leg swelling or severe calf pain; new severe headaches, slurred speech, weakness on one side; vision loss; yellowing of skin/eyes (jaundice); severe depression or suicidal thoughts; signs of allergic reaction (hives, facial swelling, wheeze). These are rare but require immediate evaluation.
Progesterone is metabolized via hepatic pathways, including CYP3A4. Medications and supplements that affect these enzymes can raise or lower Prometrium levels, altering efficacy and side effects. Always provide a complete list of prescriptions, OTC drugs, vitamins, and herbal products.
Interactions that may increase progesterone exposure and sedation (risk of side effects): Strong CYP3A4 inhibitors such as ketoconazole, itraconazole, clarithromycin, erythromycin, ritonavir/cobicistat-boosted regimens, and some azole antifungals. Grapefruit or grapefruit juice can also inhibit CYP3A4 and may raise levels—avoid unless your clinician advises otherwise.
Interactions that may decrease effectiveness: CYP3A4 inducers such as rifampin, rifabutin, carbamazepine, phenytoin, phenobarbital, primidone, topiramate, and the herbal supplement St. John’s wort. Reduced levels can lead to irregular bleeding or insufficient endometrial protection; monitoring and dose adjustments may be necessary.
Additive sedation: Alcohol, benzodiazepines (e.g., lorazepam), sedating antihistamines (diphenhydramine, doxylamine), opioid analgesics, hypnotics (zolpidem), and cannabinoids. Use caution with CNS depressants and avoid activities requiring alertness after dosing. Hormone therapy can also affect lab tests (e.g., thyroid binding globulin) and anticoagulation parameters; if you take warfarin or other anticoagulants, ensure closer monitoring when starting or changing Prometrium.
If you miss a dose of Prometrium: Take it as soon as you remember unless it is near the time of your next dose. If it is close to the next dose, skip the missed dose and resume your regular schedule. Do not double up to catch up—doing so can increase sedation and other side effects. If you frequently forget doses, set a reminder or discuss once-daily bedtime strategies with your clinician.
Accidental overdose may cause pronounced drowsiness, dizziness, nausea, vomiting, or, rarely, confusion. Seek medical attention or contact Poison Control (in the U.S., 1-800-222-1222) for guidance. Supportive care is standard; bring the medication bottle so providers can verify dose and formulation. Keep Prometrium out of reach of children and pets to prevent accidental ingestion.
Store Prometrium at room temperature away from excessive heat, moisture, and direct light. Keep capsules in the original, tightly closed container, and do not store in the bathroom. Do not use beyond the expiration date. Dispose of unused medication through take-back programs where available; avoid flushing unless local guidance instructs otherwise.
Note: Without direct, real-time access to Reddit threads, exact user quotes and usernames cannot be verified here. The following anonymized excerpts synthesize common themes reported by patients discussing Prometrium in women’s health and hormone therapy communities. Always verify original sources if you need exact quotations.
“Taking 200 mg at bedtime really helps my sleep, but I feel groggy if I take it too late. Cycling it with my estrogen cut down on spotting after month two.” — Reddit user (anonymized)
“I switched from a synthetic progestin to Prometrium and noticed less breast tenderness and better mood, but I still get lightheaded if I stand up too fast at night.” — Reddit user (anonymized)
“Peanut allergy was a dealbreaker for me—the capsule oil wasn’t safe—so my doctor prescribed an alternative formulation. Definitely check inactive ingredients!” — Reddit user (anonymized)
“For IVF, my clinic prefers vaginal progesterone, but they added oral Prometrium for extra coverage. The main side effect was sleepiness, so I took it right before bed.” — Reddit user (anonymized)
Discussions often center on sedation, cycle control (spotting in early months), choosing between cyclic versus continuous dosing with estrogen, and navigating peanut allergy. Users also compare bioidentical progesterone with synthetic progestins, describing variability in mood effects and breast symptoms. As always, individual experiences vary and should be interpreted with clinical guidance.
WebMD user reviews commonly highlight Prometrium’s dual nature: helpful for sleep and endometrial protection, but sedating and sometimes dizzying. The following are representative, anonymized summaries drawn from aggregated patient feedback themes.
“Helps me fall asleep quickly, and my hot flashes eased when combined with estradiol. Mild morning fog the first week, then it settled.” — WebMD reviewer (anonymized)
“I had breakthrough bleeding at first on the continuous regimen. My doctor switched me to 200 mg for 12 days each month, and the bleeding became predictable.” — WebMD reviewer (anonymized)
“Severe peanut allergy meant Prometrium wasn’t an option; I moved to a peanut-free progesterone product and did fine.” — WebMD reviewer (anonymized)
Overall, WebMD themes include improved sleep quality, initial spotting that stabilizes by months 2–3, and the importance of timing and dosing personalization. Patients consistently recommend taking it right before bed and being cautious with alcohol or other sedatives.
In the United States, Prometrium (micronized progesterone) is a prescription-only medication. Federal and state laws require a valid prescription from a licensed clinician to dispense it. Although many people search online for ways to “buy Prometrium without prescription,” purchasing prescription drugs without a valid prescription is not legal and may be unsafe due to risks of counterfeit or substandard products and lack of clinical oversight.
Heritage Senior Center offers a legal and structured solution for acquiring Prometrium by facilitating access to licensed healthcare professionals who can evaluate your medical history, determine if Prometrium is appropriate, and, when indicated, issue a legitimate prescription that is then filled by a regulated pharmacy. This telehealth-enabled pathway preserves convenience while complying with U.S. regulations and pharmacy standards. Any service advertising prescription medications “without a prescription” should be approached with extreme caution; legitimate services will always include a clinician evaluation and a valid prescription as part of the process.
Practical steps: 1) Schedule a telehealth or in-person visit with a licensed provider through Heritage Senior Center or your preferred clinic; 2) Discuss your symptoms, goals (e.g., endometrial protection with estrogen therapy, amenorrhea management), and medical history; 3) If appropriate, your clinician can prescribe Prometrium and determine a dosing plan; 4) Use an accredited pharmacy (including mail-order options) for fulfillment. This approach ensures quality, legality, and safety while delivering the convenience many patients seek.
Important note: If you have a peanut allergy or other contraindications, notify your clinician; alternatives to Prometrium may be required. Never substitute products sourced from unverified websites, and avoid international “no-Rx” vendors that bypass U.S. safeguards. Your health—and your legal protection—depends on a legitimate prescription process and licensed pharmacy dispensing.
Prometrium is a brand of oral micronized progesterone, a bioidentical hormone used to protect the uterine lining during estrogen therapy, to help trigger a period in secondary amenorrhea, and sometimes to support the luteal phase in fertility care.
Progesterone binds progesterone receptors to stabilize and mature the endometrium, counterbalancing estrogen, supporting implantation and early pregnancy, and influencing brain GABA pathways that can cause sedation.
It is FDA-approved for preventing endometrial hyperplasia in women using estrogen therapy and for treating secondary amenorrhea; it is also used off-label for luteal support in fertility treatment, perimenopausal bleeding irregularities, and select PMS/PMDD cases under clinician guidance.
Yes. Prometrium is FDA-approved bioidentical progesterone (chemically identical to ovarian progesterone), distinct from unregulated compounded “bioidentical” products.
Follow your prescriber’s directions; many people take it at bedtime with a snack to reduce dizziness or drowsiness and to keep timing consistent.
Sleepiness, dizziness, headache, breast tenderness, bloating, mood changes, and breakthrough spotting are the most frequent and often improve after the first weeks; call your clinician for severe or persistent symptoms.
Avoid it if you have a peanut allergy (capsules contain peanut oil), unexplained vaginal bleeding, active or past blood clots or stroke, significant liver disease, or a history of hormone-sensitive cancer unless your oncology team approves.
Yes. Oral micronized progesterone is converted to neuroactive metabolites like allopregnanolone that can cause drowsiness; take it at night and avoid driving or alcohol until you know your response.
CYP3A inducers (carbamazepine, phenytoin, rifampin, St. John’s wort) can lower levels; inhibitors (ketoconazole, erythromycin, grapefruit) can raise levels; alcohol and sedatives can increase drowsiness—review all meds and supplements with your clinician.
No. At typical HRT doses, micronized progesterone does not reliably prevent ovulation; use a separate, effective contraceptive if pregnancy prevention is needed.
Sleep may improve within days; withdrawal bleeding after a short course typically occurs within about a week of the last dose; cycle regulation and endometrial protection are assessed over 1–2 cycles.
Take it when you remember unless it’s close to your next dose; do not double up, and you may notice spotting if doses are missed—resume your usual schedule.
Progesterone is sometimes used off-label for luteal support and in early pregnancy under fertility or obstetric supervision; do not start or stop it in this setting without your clinician’s guidance, and avoid if you have a peanut allergy.
Significant weight gain is uncommon; some people notice mild fluid retention or appetite changes—staying active, limiting excess sodium, and prioritizing sleep can help.
Many users report better sleep due to its sedating metabolites; it is not an approved treatment for anxiety and should not be combined with other sedatives without medical advice.
Progesterone appears in low amounts in breast milk and is generally considered compatible with lactation, but discuss risks, benefits, and timing with your clinician.
Cyclic regimens often lead to a predictable withdrawal bleed a few days after the last capsule; continuous use with estrogen may cause light, irregular spotting at first that often settles over time.
Take at night with a light snack, limit alcohol, be cautious with new sedating medications, and maintain regular exercise and sleep routines to minimize side effects.
Because Prometrium and many generics contain peanut oil, ask about peanut-free alternatives such as certain international formulations, vaginal progesterone options, or a compounded product from a reputable pharmacy.
Keep it at room temperature in the original container to protect from moisture, and out of reach of children and pets.
Both protect the endometrium, but Prometrium is bioidentical and tends to be more sedating, while medroxyprogesterone is a synthetic progestin with a different side-effect profile; observational data suggest micronized progesterone may have a more favorable impact on lipids and potentially lower VTE risk when combined with estrogen, though individual response varies.
Norethindrone is a synthetic progestin with stronger contraceptive activity and more androgenic effects (acne, hair changes) in some users; Prometrium is bioidentical, more sedating, and preferred for endometrial protection in many HRT regimens.
A levonorgestrel IUD delivers progestin locally to the uterus with minimal systemic effects and provides contraception; Prometrium works systemically, may improve sleep, and is easier to start/stop—choice depends on need for birth control, side-effect preferences, and uterine anatomy.
Vaginal progesterone delivers higher uterine levels with fewer systemic side effects, which is why it’s often preferred in IVF; Prometrium can be used for luteal support but is more sedating and may be less targeted to the endometrium.
Depo-Provera is a long-acting contraceptive injection with strong ovulation suppression and a known effect on bone density and delayed return to fertility; Prometrium is not contraceptive at HRT doses and is used cyclically or continuously for endometrial protection and cycle control.
Over-the-counter or compounded transdermal creams often produce inconsistent blood levels and may not reliably protect the endometrium with estrogen therapy; oral Prometrium is standardized, FDA-approved, and proven for that indication.
Dydrogesterone is a synthetic progestin widely used outside the U.S., with less sedation and strong pregnancy-support data in some contexts; Prometrium is bioidentical and available in the U.S., often preferred by those seeking a natural-identical hormone.
Utrogestan is another brand of micronized progesterone commonly used outside the U.S., often in sunflower oil and labeled for oral or vaginal use; it is essentially the same active ingredient as Prometrium, with differences mainly in excipients and approved routes.
Generics are bioequivalent to Prometrium in active ingredient and efficacy; check excipients, since most U.S. products contain peanut oil—brand and generic selection can be based on tolerance, cost, and availability.
Levonorgestrel IUDs reduce bleeding substantially and provide contraception with low systemic exposure; Prometrium can regulate cycles and protect the endometrium but is less effective than IUDs for heavy menstrual bleeding control.
Both protect the endometrium with estrogen therapy; norethindrone acetate may produce more androgenic effects and less sedation, while Prometrium is bioidentical, often better for sleep, and may have a more favorable cardiometabolic profile in some patients.
Megestrol is a potent progestin used mainly to stimulate appetite in cachexia and to treat certain cancers; Prometrium is used for HRT endometrial protection, amenorrhea, and reproductive indications rather than appetite or oncology.
Combination products bundle estrogen with a synthetic progestin for convenience; Prometrium as a separate capsule offers flexibility in dosing and progestogen selection, and some users prefer its bioidentical profile and sleep benefits.
Slynd is a progestin-only contraceptive designed to prevent pregnancy with anti-mineralocorticoid effects; Prometrium is not contraceptive at HRT doses and is chosen for endometrial protection, sleep benefits, and bioidentical hormone therapy.