Progesterone Medications

Progesterone is a progestogen hormone used in medications to treat menopausal symptoms, support fertility, and prevent uterine issues by mimicking natural hormonal functions.

Prometrium

Progesterone

$2.23 per pill

100 | 200mg

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About Progesterone

Progesterone is a naturally occurring steroid hormone that belongs to the progestogen class. In clinical practice it is used to support the luteal phase of the menstrual cycle, to treat abnormal uterine bleeding, and to provide hormone-replacement therapy (HRT) for post-menopausal women. Brand-name products such as Prometrium, Utrogestan and Crinone contain micronized progesterone, while generic capsules and vaginal gels are widely available through our online pharmacy. Off-label, progesterone is sometimes employed in assisted-reproductive technologies to improve implantation rates and, in selected obstetric settings, to reduce the risk of preterm birth. Its primary action is to bind intracellular progesterone receptors, altering gene transcription that prepares the endometrium for implantation and modulates uterine contractility. Understanding how progesterone works helps patients anticipate its therapeutic timeline, potential side effects, and the importance of professional monitoring.

What is Progesterone?

Progesterone is a steroid hormone classified as a progestogen. The Singapore Health Sciences Authority (HSA) recognizes it as a regulated hormone for HRT and reproductive indications, and the U.S. Food and Drug Administration (FDA) approved micronized progesterone for hormone-replacement therapy in 1998. The European Medicines Agency (EMA) subsequently expanded its label to include luteal-phase support in assisted reproduction. At the molecular level, progesterone binds to intracellular progesterone receptors (PR-A and PR-B), forming a hormone-receptor complex that translocates to the nucleus and regulates transcription of target genes involved in endometrial maturation, cervical mucus production, and suppression of myometrial contractility. Both branded formulations (e.g., Prometrium® tablets, Crinone® gel) and generic micronized capsules are stocked by our pharmacy service, offering patients flexible options for oral, vaginal, or intramuscular delivery.

How Progesterone Works

Mechanism of Action

Progesterone diffuses across cell membranes and binds with high affinity to nuclear progesterone receptors. The activated receptor complex recruits co-activators and binds progesterone response elements on DNA, modulating transcription of genes that promote secretory transformation of the endometrium and inhibit estrogen-driven proliferation. In the myometrium, progesterone reduces expression of oxytocin receptors and calcium-channel activity, leading to decreased uterine contractility.

Therapeutic Effects

By preparing the uterine lining, progesterone creates a receptive environment for embryo implantation, which explains its routine use after in-vitro fertilisation (IVF). In HRT, it counteracts estrogen-induced endometrial proliferation, lowering the risk of hyperplasia. When administered during the luteal phase, it stabilises the menstrual cycle and alleviates symptoms of luteal-phase deficiency such as spotting or dysmenorrhoea.

Onset and Duration

Oral micronized progesterone reaches peak plasma concentrations within 2-3 hours, producing measurable endometrial changes by day 5 of therapy. Vaginal gels achieve higher local concentrations with a slower systemic rise, often resulting in symptom relief within 48 hours. The elimination half-life of oral progesterone is approximately 5 hours, while vaginal administration extends the effective exposure for up to 12 hours, allowing once-daily dosing for most indications.

Approved Uses and Applications

Approved Indications

Hormone-replacement therapy for post-menopausal women when combined with estrogen to protect the endometrium (FDA, EMA, HSA).
Luteal-phase support in assisted reproductive technology cycles, typically initiated after oocyte retrieval and continued through early pregnancy (EMA).
Management of abnormal uterine bleeding caused by estrogen dominance or anovulatory cycles (HSA).
Prevention of preterm birth in women with a history of spontaneous preterm delivery, as endorsed by selected obstetric guidelines (American College of Obstetricians and Gynecologists).

Off-Label Uses

Progesterone is sometimes prescribed for endometriosis-related pain, as an adjunct in certain breast-cancer protocols, and for neuro-protective strategies after traumatic brain injury. These applications are not officially approved by regulatory agencies and should be considered experimental.

Clinical Efficacy

A double-blind trial published in The New England Journal of Medicine demonstrated a 30 % reduction in miscarriage rates when vaginal progesterone was used for luteal support in IVF cycles. In a meta-analysis of HRT studies in The Lancet, combined estrogen-progesterone therapy lowered the incidence of endometrial hyperplasia from 4.2 % to .8 % over a 2-year period. These data underscore progesterone’s role in both reproductive success and endometrial protection.

Buying Progesterone from Our Online Pharmacy

Why Choose Our Service

Access to progesterone can be limited in some retail outlets, especially for specific formulations such as vaginal gels. Through our platform, patients in Singapore obtain authentic, WHO-certified products with discreet packaging and secure delivery.

Brand Names and Generic Options

Prometrium® (oral micronized tablets)
Utrogestan® (capsules)
Crinone® (vaginal gel)
Endometrin® (vaginal inserts)

Generic micronized progesterone is typically 30-40 % less expensive, delivering the same therapeutic effect while reducing out-of-pocket costs.

Quality & Safety

We partner with licensed international pharmacies that comply with Good Manufacturing Practice (GMP) standards and are inspected by the Singapore HSA.

Pricing & Access

Competitive pricing, combined with a Lifetime 10 % discount on all reorders, makes long-term therapy more affordable.

Discreet Delivery

Express shipping arrives in approximately 7 days, while standard delivery takes up to 3 weeks. Every package is sealed in plain, tamper-evident envelopes to protect privacy.

Dosing, Formulations & Administration

Available Formulations

Oral micronized capsules/tablets: 100 mg, 200 mg, 400 mg
Vaginal gel or inserts: 90 mg (Crinone®), 200 mg (Endometrin®)
Intramuscular injection: 25 mg, 100 mg in oil solution

Typical Dosing Ranges

For HRT, clinicians often start adults at 100 mg orally at bedtime, adjusting to 200 mg if symptoms persist. In IVF cycles, a common regimen is 90 mg of vaginal gel nightly from the day of embryo transfer through week 8 of gestation. Luteal-phase deficiency may be managed with 200 mg oral progesterone twice daily for 10-14 days, then tapering based on response. These examples illustrate standard practice; a qualified healthcare provider must individualise the dose.

Administration Guidelines

Oral capsules should be taken with food to improve absorption and reduce gastrointestinal upset. Vaginal gels are best inserted at bedtime to minimise leakage. Intramuscular injections require rotation of injection sites to avoid local irritation. Patients should avoid grapefruit juice, which can modestly increase systemic progesterone levels through CYP3A4 inhibition.

A clinician will determine the exact regimen after evaluating medical history, concomitant medications, and treatment goals.

Safety Profile & Considerations

Common Side Effects

Headache (≈ 12 % of users)
Breast tenderness (≈ 10 %)
Nausea or abdominal bloating (≈ 8 %)
Dizziness (≈ 5 %)
Mood swings (≈ 4 %)

These events are usually mild and resolve within a few weeks of continued therapy.

Serious Adverse Events

Rare but serious risks include venous thromboembolism, especially when combined with estrogen, and severe allergic reactions such as anaphylaxis. Immediate medical attention is required for sudden chest pain, shortness of breath, or swelling of the face and throat.

Contraindications

Active or history of thromboembolic disease
Known or suspected estrogen-dependent breast cancer
Uncontrolled hypertension or severe liver disease
Pregnancy, except for approved obstetric indications (e.g., prevention of preterm birth)

Drug Interactions

CYP3A4 inhibitors (ketoconazole, itraconazole) may increase progesterone concentrations, heightening side-effect risk.
CYP3A4 inducers (rifampin, carbamazepine) can lower plasma levels, potentially reducing efficacy.
Concurrent estrogen therapy amplifies the risk of clot formation; careful monitoring is advised.

Special Populations

Pregnancy: Certain formulations are indicated for specific gestational windows; otherwise, routine use is avoided.
Breastfeeding: Progesterone passes into breast milk in low amounts; clinicians weigh benefits against potential infant exposure.
Elderly: Age-related hepatic decline may prolong drug clearance; dose adjustments are sometimes necessary.
Renal or hepatic impairment: Severe dysfunction warrants lower starting doses and close laboratory monitoring.

Frequently Asked Questions

How does progesterone differ from estrogen in hormone-replacement therapy? Progesterone counteracts estrogen-driven endometrial proliferation, reducing the risk of hyperplasia, whereas estrogen primarily alleviates vasomotor symptoms. The two hormones are often combined to provide balanced HRT.
How long before progesterone produces noticeable effects for irregular periods? Oral micronized progesterone typically begins to regulate menstrual bleeding within 5-7 days, while vaginal preparations may show improvement by the second cycle.
What should I do if I experience persistent breast tenderness while taking progesterone? Mild tenderness is common; applying warm compresses and wearing a supportive bra can help. If pain intensifies or is accompanied by a lump, schedule a clinical evaluation promptly.
Can I take progesterone with my antihypertensive medication? No direct pharmacokinetic interaction is known, but both drugs can influence fluid balance. Discuss dosage adjustments with your prescriber to ensure blood pressure remains controlled.
Does taking progesterone with food affect its absorption? Consuming the oral capsule with a meal modestly enhances bioavailability and reduces gastrointestinal upset. Vaginal gels are unaffected by food intake.
Are there any foods I should avoid while on progesterone? Grapefruit and grapefruit juice can inhibit CYP3A4, potentially raising progesterone levels. Limiting these foods helps maintain stable hormone concentrations.
Is progesterone safe for long-term use in post-menopausal women? Long-term combined estrogen-progesterone therapy has been studied for up to 5 years, showing acceptable safety when patients are screened for cardiovascular and cancer risk factors. Ongoing monitoring is essential.
What monitoring is required during progesterone therapy? Baseline and periodic assessments of blood pressure, lipid profile, liver function, and, when combined with estrogen, coagulation parameters are recommended.
What information should I provide my doctor when discussing progesterone?
- Complete list of current prescription, over-the-counter, and herbal products
- History of clotting disorders, breast or uterine cancer, liver disease, and cardiovascular conditions
- Specific symptoms you aim to treat (e.g., irregular bleeding, menopausal hot flashes, fertility support)
- Any previous hormone-therapy experiences and side-effect profiles

Disclaimer

The information provided about progesterone is for general knowledge only. It does not replace professional medical consultation or the official prescribing information for medications containing this ingredient. All treatment decisions, including dosing, formulation selection, and monitoring, should be made under the supervision of a qualified healthcare provider who can assess individual medical history, current medications, and specific health needs. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to medications containing progesterone for individuals who may have limited availability through traditional pharmacies, prescription-based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication containing progesterone.