Basic Prometrium Information

• INN (International Nonproprietary Name): Progesterone
• Brand Names Available In Australia: Prometrium (softgels 100 mg, 200 mg)
• ATC Code: G03DA04
• Forms & Dosages: Soft capsules 100 mg and 200 mg in blister packs (30/90); vaginal capsules/softgels 100 mg and 200 mg (boxes of 15/30); compounding powders (variable, pharmacy‑prepared)
• Manufacturers In Australia: AbbVie (Prometrium)
• Registration Status In Australia: Registered as prescription medicine (Prometrium marketed in Australia/NZ)
• OTC / Rx Classification: Prescription Only (Rx)

Key Findings From Recent Trials

What do the latest studies say about micronised progesterone and endometrial protection?

Major 2022–mid‑2024 Australian and global studies consistently show two clear clinical signals for micronised progesterone: reliable endometrial protection when given with oestrogen in HRT, and useful restoration of menstrual bleeding in secondary amenorrhoea.

Multicentre IVF studies and large meta‑analyses reaffirm that vaginal administration achieves higher endometrial concentrations while producing similar systemic progesterone levels to oral dosing.

European and Asian practice documents continue to reference off‑label vaginal use of oral softgels for local uterine effect, and the approach is discussed among Australian reproductive specialists as an option in clinic protocols.

Main outcomes reported include effective prevention of endometrial hyperplasia in combined HRT cycles and predictable induction of withdrawal bleeding in amenorrhoea regimens.

Safety observations from post‑market surveillance echo expected adverse effects such as drowsiness and breast tenderness, and reinforce absolute contraindications including severe hepatic dysfunction and thromboembolic disease.

TGA adverse event reports up to 2024 align with international pharmacovigilance, noting rare severe hepatic events and the need for caution in women with cardiovascular risk.

Regulatory listings for Prometrium (AbbVie) and Utrogestan (Besins) remain active in multiple markets with softgel strengths of 100 mg and 200 mg commonly available.

Clinical implication: balance the clear benefit of endometrial protection with each patient’s thrombotic and hepatic risk and consider the route of administration when uterine concentration is important.

Clinical Mechanism Of Action

How does micronised progesterone actually work in the body?

Layman’s Explanation

Progesterone is the natural hormone that prepares the womb lining for pregnancy and counterbalances oestrogen in HRT.

Micronised progesterone softgels such as Prometrium provide a bio‑identical form of that hormone to regulate bleeding and support luteal‑phase processes.

Scientific Breakdown

Micronisation improves oral absorption and bioavailability compared with larger crystalline forms.

After oral ingestion progesterone is absorbed in the gut and undergoes first‑pass hepatic metabolism which produces neuroactive metabolites such as allopregnanolone.

Those metabolites explain sedative and mood effects often reported with oral dosing.

Receptor Interactions

Progesterone binds progesterone receptor isoforms PR‑A and PR‑B in the endometrium and brain, modulating gene expression to stabilise endometrial proliferation from oestrogen exposure.

Metabolism And Delivery

Oral routes give systemic exposure and systemic metabolites; vaginal administration concentrates uterine levels with reduced systemic metabolite formation.

The ATC classification is G03DA04, placing progesterone among pregnen‑derivative progestogens.

Clinical consequence: route and dose determine the balance between endometrial protection, systemic side effects such as fatigue and dizziness, and patient convenience.

Scope Of Approved And Off‑Label Use

Which conditions is Prometrium approved for, and what off‑label trends should prescribers know?

Australian Approvals (TGA‑Listed, PBS Inclusion)

Prometrium is registered and marketed in Australia and New Zealand as micronised progesterone softgels at 100 mg and 200 mg strengths.

The registered indications internationally include secondary amenorrhoea and endometrial protection when prescribed with oestrogen in postmenopausal HRT.

Prometrium is prescription‑only (Rx) in Australia, and PBS subsidy status varies by indication and time, so clinicians should check current PBS schedules for each patient.

Notable Off‑Label Trends In Australian Practice

Off‑label vaginal administration of oral capsules is practised in parts of Europe and Asia and is discussed among Australian fertility and reproductive clinics for local uterine effect.

Community pharmacies sometimes compound specific formulations or advise on vaginal use when directed by a prescriber, with documentation of informed consent advised.

Counselling should highlight excipient warnings such as peanut oil in some formulations and absolute contraindications including thrombotic and hepatic disease.

Rural prescribers commonly rely on telehealth specialist input and local pharmacist support for supply and dosing adjustments when access to specialists is limited.

Dosage Strategy

What dosing patterns should patients expect for common indications?

General Dosing

Prometrium softgel capsules are typically available as 100 mg and 200 mg micronised progesterone formulations in blister packs of 30 or 90.

Bedtime dosing is commonly recommended to reduce sedative effects because oral progesterone metabolites are associated with drowsiness.

Delivery format affects exposure: oral dosing produces systemic concentrations; vaginal dosing concentrates drug in the uterus.

Condition‑Specific Dosing (PBS Recommendations)

For secondary amenorrhoea the documented regimen is 400 mg orally once daily at bedtime for 10 days, repeated as clinically indicated.

For endometrial protection with oestrogen therapy a commonly cited regimen is 200 mg orally once nightly for 12 days of a 28‑day cycle.

Do not use in children; use caution in elderly patients who may have increased sensitivity, and avoid in severe hepatic dysfunction.

If a dose is missed, take as soon as remembered unless close to the next scheduled dose and do not double up.

Safety Protocols

Who should not take micronised progesterone and what adverse effects should be watched for?

Contraindications (Australian Guidelines)

Absolute contraindications include severe liver dysfunction, known or suspected breast cancer or other hormone‑dependent malignancy, undiagnosed abnormal vaginal bleeding, and current or past thromboembolic disease (DVT, PE, stroke, MI).

Allergy to peanut oil is an absolute contraindication for formulations containing that excipient.

Pregnancy is an exclusion for most indications; check product information for indication‑specific guidance.

Adverse Effects (Post‑Market Pharmacovigilance)

Common side effects are headache, breast tenderness, abdominal cramps, bloating, dizziness, fatigue and drowsiness, mood changes and nausea.

TGA and international pharmacovigilance report sedation as a frequently observed effect and rare hepatic events have been reported post‑market.

In overdose symptoms may include marked sedation, nausea, vomiting and withdrawal bleeding; provide supportive care and seek urgent medical review for severe symptoms.

Monitoring recommendations include baseline hepatic function and cardiovascular risk assessment for prolonged HRT use, with periodic review.

Interaction Mapping

Which medicines, foods or lifestyle factors change how progesterone works?

Food Interactions (Alcohol, Coffee, Diet In Australia)

Take progesterone at night to offset drowsiness that can be amplified by alcohol and other sedatives.

Alcohol and sedative drugs can increase somnolence when combined with progesterone’s sedative metabolites.

Caffeine may mask sedation but does not alter progesterone efficacy, and a high‑fat meal may increase oral absorption, so advise consistent administration with regard to meals.

Drug Combinations To Avoid (TGA Safety Alerts)

Hepatic enzyme inducers such as rifampicin, phenytoin, carbamazepine and St John’s wort can lower progesterone levels and may reduce effectiveness.

Concurrent use with oestrogen therapies requires cardiovascular and thrombotic risk review, and anticoagulant therapy should be carefully documented and monitored.

TGA safety alerts emphasise avoiding progesterone in known thrombotic disease and highlight peanut oil excipient warnings for allergic patients.

In fertility settings coordinate dosing with clinic protocols to avoid duplication with other progestins or oestrogens.

Patient Experience Analysis

What do Australian patients report about tolerability and access for micronised progesterone?

Australian Survey Data

Clinical audits and pharmacy feedback show many patients prefer micronised progesterone as a “body‑identical” option compared with synthetic progestins.

Common patient‑reported benefits include improved sleep and reduced menstrual irregularity for some women.

Reported downsides include mood swings, sedation and occasional weight change, mirroring the expected side‑effect profile.

Forum And Pharmacy Trends

Community pharmacy enquiries commonly relate to bedtime dosing, off‑label vaginal use and peanut allergen questions, especially among fertile‑age women seeking local effect for luteal support.

Online forums show mixed tolerability but an overall trend of patients choosing micronised progesterone for perceived naturalness.

Rural patients often rely heavily on pharmacist counselling and telehealth scripts, and price sensitivity affects whether patients pursue private prescriptions when PBS criteria are not met.

Distribution And Pricing Landscape

How easy is it for Australians to get Prometrium and what does it cost?

National Pharmacy Chains (Chemist Warehouse, Priceline, TerryWhite)

Major chains such as Chemist Warehouse, Priceline and TerryWhite generally stock or can order Prometrium softgels in 100 mg and 200 mg strengths.

Price varies by pack size and supplier, and absence of PBS subsidy for a given patient or indication often means a private prescription cost applies.

Online Pharmacy Growth And Telehealth E‑Scripts

Telehealth and electronic prescriptions have expanded access and supported home delivery, which is particularly useful for remote and rural patients.

In our online pharmacy, prometrium is available without a prescription, with discreet delivery to Australia in 5-14 days.

PBS Vs Private Cost Comparisons

PBS coverage is indication‑specific and can change, so clinicians and pharmacists should verify current listings before counselling on cost.

When PBS subsidy is not available patients commonly compare private prices across chains and online pharmacies to decide on brand or generic options.

Alternative Options

What other progestogen options are available if micronised progesterone isn’t suitable?

Comparison Table Of PBS And Non‑PBS Options

• Micronised Progesterone (Prometrium): Bio‑identical progesterone available as softgels; may not be PBS‑subsidised for all indications.
• Medroxyprogesterone (Provera): Synthetic progestin with broader PBS availability for some indications; tablets and injectables available.
• Dydrogesterone (Duphaston): Oral synthetic progestin used in luteal support with different side‑effect profile and subsidy status.

Pros And Cons Checklist

• Micronised progesterone: pros—bio‑identical, well tolerated by many; cons—cost if not PBS‑listed, peanut oil allergy risk, sedative effects.
• Medroxyprogesterone: pros—widely available and often subsidised; cons—synthetic, different tolerability.
• Dydrogesterone: pros—oral convenience; cons—not identical to endogenous progesterone.

Pharmacists should review PBS listings at the point of care and advise on therapeutic substitution where clinically appropriate.

Regulatory Status

How do TGA and PBS rules shape access to Prometrium in Australia?

TGA Approval Framework

Prometrium has TGA registration as a prescription medicine in Australia, indicating assessment of quality, safety and efficacy.

Sponsors such as AbbVie and generic manufacturers must comply with labelling rules including excipient allergen warnings like peanut oil.

TGA adverse event reporting informs ongoing safety updates and contraindication reinforcement.

PBS Subsidy Process

For a PBS subsidy to apply, sponsors submit evidence of cost‑effectiveness and clinical need for specific indications, and PBS listings are indication‑specific.

Where PBS listing does not apply, prescribers and patients use private prescriptions and pharmacists can advise on cheaper generics or alternatives.

Consolidated FAQ

What do patients ask most about Prometrium in Australia?

• Is Prometrium the same as “natural” progesterone?

  Yes; Prometrium is micronised bio‑identical progesterone (INN: progesterone) in softgel form at 100 mg and 200 mg strengths.

• Will my PBS cover Prometrium?

  PBS coverage depends on the indication and current listings; check PBS schedules or ask your prescriber or pharmacist for the latest status.

• Can I use oral capsules vaginally?

  Vaginal administration of oral capsules is practised off‑label in some regions and by some clinics; discuss with your clinician and ensure informed consent.

• Any allergy concerns?

  Some formulations contain peanut oil and are contraindicated for patients with peanut allergy; pharmacists should check excipients before dispensing.

• What happens if I miss a dose?

  Take as soon as you remember unless it is near the next dose; do not double up and seek urgent care for severe overdose symptoms such as marked sedation or vomiting.

Visual Guide

What visuals will help patients and clinicians understand access, dosing and safety?

Suggested infographics for designers include a national pharmacy distribution map showing availability across Chemist Warehouse, Priceline and TerryWhite with rural versus urban stocking density.

Include a PBS versus private cost bar chart for example pack sizes (illustrative only and verify current prices before publishing).

Provide a simple flowchart linking indication to route selection and recommended dosing (for example, 400 mg nightly for 10 days for secondary amenorrhoea; 200 mg nightly for 12 days per 28‑day cycle for endometrial protection).

Add a contra‑indication badge strip with severe hepatic disease, thromboembolism, peanut allergy and pregnancy cautions and an embedded pharmacist counselling checklist.

Storage And Transport

How should Prometrium be stored at home and handled by pharmacies in Australian climates?

Household Storage Under Australian Climate

Store Prometrium below 25°C and protect it from moisture and light, keeping it in the original blister packaging.

Do not refrigerate or freeze the product.

Advise patients in hot inland regions to keep blister packs in cool shaded places and to avoid bathroom humidity or leaving packs in a hot car.

When travelling in summer recommend insulated pouches and avoiding prolonged car storage in direct sun.

Cold‑Chain Logistics For Pharmacies

Pharmacies should store stock under manufacturer‑specified conditions and monitor for heat exposure, especially during summer months.

Online pharmacies and couriers should avoid temperature extremes during transit, use tracked deliveries and consider express options in hot months to protect product integrity.

Rural pharmacies must plan stock rotation and liaise with wholesalers to avoid supply gaps.

Guidelines For Proper Use

What should pharmacists say when counselling patients about Prometrium in Australia?

Pharmacist Counselling Style In Australia

Start by confirming the indication and reviewing medical history for thrombotic events, liver disease, breast cancer and allergies.

Ask specifically about peanut allergy and current medicines including enzyme inducers such as rifampicin or St John’s wort.

Advise bedtime dosing to reduce sedative effects and explain missed‑dose instructions clearly, documenting advice in the patient profile.

Offer cost options and check PBS eligibility, and if discussing off‑label vaginal use ensure informed consent and clear documentation.

National Health Authority Recommendations

Follow TGA product information and relevant clinical guidance for endometrial protection and management of secondary amenorrhoea.

Recommend baseline checks such as hepatic function and a cardiovascular risk assessment for ongoing HRT and schedule periodic reviews.

For fertility services align with reproductive endocrinology protocols and ensure clear communication between prescriber and dispensing pharmacist.

Delivery Across Australia

Final Notes For Prescribers And Pharmacists

Which practical checks reduce risk and improve patient outcomes when dispensing Prometrium?

Confirm indication and dosing against the registered regimens: 400 mg nightly for 10 days for secondary amenorrhoea and 200 mg nightly for 12 days per 28‑day cycle for endometrial protection when combined with oestrogen.

Check absolute contraindications including severe hepatic dysfunction, thromboembolic history and peanut allergy before supply.

Screen medication histories for enzyme inducers and sedative co‑medications, and counsel on bedtime dosing and the potential for drowsiness.

Document counselling, any off‑label use rationale and informed consent when applicable, and arrange follow‑up monitoring with the prescriber for long‑term HRT users.