Progesterone

Progesterone is a hormone the body makes after ovulation. It prepares and stabilises the lining of the uterus so a pregnancy can begin. As a prescription medicine, it is used with estrogen to protect the uterine lining during menopause treatment, and to bring on a period in people whose cycles have stopped. Prescription forms include capsules taken by mouth, vaginal gels and inserts, and injections.

This page explains, in everyday language, what the hormone does, what the approved products are cleared to treat, what side effects and warnings matter most, and what drives the monthly cost when you are paying yourself. It is a reference page, not a treatment plan.

What progesterone is and what it does in the body

Progesterone is a steroid hormone made mainly by the ovaries after an egg is released, and later by the placenta during pregnancy. Its main job is to change the uterine lining from a growing state to a receptive state. Estrogen thickens the lining; this hormone matures it and keeps it quiet.

When no pregnancy occurs, levels fall and a period follows. That rise and fall is why the second half of the menstrual cycle is often called the luteal phase. A clear overview of this cycle role is published by a major US hospital system, in Cleveland Clinic’s patient explainer on the hormone.

It also acts outside the uterus. Receptors sit in breast tissue, the brain and blood vessels. In the brain, one of its breakdown products acts on the same calming receptors that sedative medicines target, which is reviewed in a peer reviewed overview of progesterone’s wide ranging effects.

How it can make you feel

People sometimes call it the calming or happy hormone because of that brain effect. Many report drowsiness or a settled feeling, especially with oral capsules. Others notice the opposite: low mood, irritability or tearfulness. Both patterns are recognised, and neither is a sign you are doing something wrong. Feeling changes are worth reporting to whoever prescribed it rather than absorbing quietly.

What prescription progesterone is approved to treat

Approved uses come from the product label, not from popularity. For oral micronized capsules, US labeling supports two uses. The first is preventing endometrial hyperplasia in postmenopausal women who still have a uterus and are taking conjugated estrogens. Hyperplasia means an overgrown uterine lining, which can raise the risk of uterine cancer if estrogen is taken alone. The second is secondary amenorrhea, meaning periods that stopped after having been regular.

Other product forms carry their own approved uses. Vaginal gels and inserts are approved to support the uterine lining during assisted reproduction, and injectable forms have long standing uses in amenorrhea and abnormal uterine bleeding linked to hormone imbalance. A plain summary of these product roles sits in the MedlinePlus drug information page for this hormone.

Search interest runs wider than the label. People look for it for sleep, premenstrual symptoms, perimenopausal bleeding, luteal support and preterm birth risk. Some of those uses have real research behind them and some do not. Prescribing outside the label is legal and common in medicine, but it is a clinical judgement call, not an approved indication, and it deserves a direct conversation about evidence.

Micronized progesterone versus synthetic progestins

These two groups get mixed up constantly, and the difference matters when you read warnings. Micronized progesterone is chemically identical to the hormone the body makes, ground into fine particles so the gut can absorb it. Progestins such as medroxyprogesterone or norethindrone are lab designed molecules that act on the same receptor but are built differently.

Marketing language complicates this further. The word bioidentical is used for FDA approved micronized products and for custom mixed preparations that were never reviewed by regulators. The two are not the same thing, and the section below separates them.

Signs of low progesterone, and what high levels usually mean

Low levels most often show up as cycle problems. Irregular or missing periods, spotting between periods, very short cycles, and difficulty conceiving are the patterns clinicians look at. Because levels swing across the cycle, a single blood test says little unless it is timed correctly, usually about a week after ovulation.

Symptoms alone cannot confirm a deficiency. Fatigue, low mood, poor sleep, breast tenderness and headaches overlap with thyroid problems, iron deficiency, perimenopause, stress and sleep disorders. That is why a careful history and targeted testing come before hormones, not after.

High readings usually have a simple explanation: pregnancy, the luteal phase itself, or taking a supplemental hormone. Less commonly, ovarian cysts or rare adrenal conditions raise levels. Symptoms people describe as high progesterone, such as bloating, breast soreness, sleepiness and mood swings, tend to overlap with the side effects listed below. If you are tracking your cycle to time testing or conception attempts, this estimator can help you work out roughly when ovulation falls.

Side effects of progesterone pills, gels and injections

Most side effects are dose related and form related rather than dangerous. Oral capsules are the form most often linked with drowsiness, dizziness and a groggy feeling, which is why labeling directs bedtime dosing for the uterine lining use. Driving or operating machinery soon after a dose is a genuine caution, not a formality. Mayo Clinic’s reference page on the oral route and its recognised effects covers this in detail.

Commonly reported effects with oral capsules include headache, breast tenderness or pain, joint aches, bloating, nausea, urinary symptoms, mood changes and abdominal cramping. Some people notice spotting or a change in bleeding pattern when starting.

Vaginal gels and inserts shift the side effect profile. Local irritation, discharge, itching and mild cramping are the usual complaints, and systemic drowsiness is generally less prominent because the medicine acts more locally. Injections in oil can cause soreness, swelling or a lump at the injection site.

Effects that need prompt attention are different in kind. Sudden severe headache, vision changes, chest pain, one sided leg pain or swelling, trouble breathing, severe abdominal pain, yellowing of the eyes or skin, or unusual heavy vaginal bleeding are all reasons to seek medical care rather than wait for a follow up appointment.

The boxed warning, contraindications and precautions

Progesterone capsules carry a boxed warning, the strongest warning US labeling uses. It applies to estrogen plus progestin therapy as a combination. In the Women’s Health Initiative trial, that combination was linked to higher rates of deep vein thrombosis, pulmonary embolism, stroke, heart attack and invasive breast cancer, and a related memory study found a higher rate of probable dementia in women aged 65 and older. The label states plainly that estrogen plus progestin should not be used to prevent heart disease or dementia. The full warning text sits with the product label on DailyMed, the NIH label repository, and the trial itself is summarised by the NHLBI, which ran the study.

That is context, not a verdict. The same labeling supports using a progestogen alongside estrogen precisely to reduce uterine risk, and risk figures differ by age, time since menopause, dose, route and personal history. What matters is that the decision is made with your own risk factors on the table.

Labeling also lists situations where these products should not be used. These include known or suspected pregnancy in some products, undiagnosed abnormal genital bleeding, known or suspected breast cancer, active or past blood clots in the legs or lungs, recent stroke or heart attack, liver problems, and known allergy to any ingredient. One ingredient point catches people out: oral capsules are typically made with peanut oil, so a peanut allergy is a hard stop. Smoking, high blood pressure, diabetes, obesity and a family history of clots all raise the stakes and belong in the conversation.

Estrogen is the other half of most menopause regimens, so its own warnings apply in parallel. If your program pairs the two, read up on Estradiol Safety And Warnings as well, then browse the Full Medication Index for other hormones a program may add.

Drug interactions and what to tell your prescriber

The liver clears this hormone using the CYP3A4 enzyme system, so medicines that speed up or slow down that system can change blood levels. Strong enzyme inducers such as rifampin, carbamazepine, phenytoin, phenobarbital and St John’s wort can lower levels and reduce the effect. Inhibitors such as ketoconazole, itraconazole, clarithromycin, certain HIV medicines and grapefruit juice can push levels up and make side effects more likely.

Sedating medicines deserve their own mention. Alcohol, sleep aids, opioid pain medicines, benzodiazepines, muscle relaxants and some antihistamines can add to the drowsiness that oral capsules already cause. The combination can leave you far more impaired than either alone.

Interaction checks only work with a complete list. Include prescriptions, patches, injections, over the counter products, herbal supplements, and any hormone creams you buy yourself. Hormone products from more than one prescriber are a common source of accidental doubling up. Tell your clinician if you smoke, if you have had a clot, or if you are due for surgery or long haul travel, since immobility raises clot risk. Practical background on medication safety questions appears across our Latest Editorial Analysis.

Compounded progesterone versus FDA approved products

Compounded preparations are mixed to order by a pharmacy: creams, troches, suppositories, custom strengths, or blends with estrogen or testosterone. They are not FDA approved and are not reviewed for safety, effectiveness or manufacturing quality before they are sold, even though the active hormone in an approved capsule is the same molecule. The agency explains this distinction in its questions and answers on human drug compounding.

Compounding exists for real reasons: an allergy to an ingredient such as peanut oil, a strength no approved product offers, or a form a patient cannot tolerate. What varies between pharmacies is more than branding. Potency testing, sterility standards for injectables, absorption from creams, and batch to batch consistency all differ. Pharmacies operating under section 503A serve individual prescriptions, while 503B outsourcing facilities make larger batches under stricter federal oversight.

Absorption is the sticking point with creams and troches. Blood levels from skin applied hormone are unpredictable, and it is not clear that they reliably protect the uterine lining the way approved products do. A National Academies review of compounded bioidentical hormone therapy found the evidence base thin and urged caution, in its report on compounded hormone therapy. If a program offers a compounded route, ask which pharmacy fills it, what testing that pharmacy does, and why an approved product will not work for you.

What progesterone costs without insurance

Cost splits cleanly into two routes that should never be added together: cash pay, meaning what you hand over yourself, and the plan or membership fee when insurance is billed, which excludes copays and deductibles. For the self-pay programs tracked on this page, the low end sits at $23 a month and the median at $39 a month. Advertised figures move, so treat any number as a snapshot and check before you commit.

Several things move that monthly figure. The form matters most: generic oral capsules, vaginal gels or inserts, injections and compounded creams sit at different levels. Brand versus generic matters, as does the dose strength and how many units a month you need. Then come the program layers: a consultation or membership fee, lab work if it is required, shipping, and whether the quoted price includes estrogen when the plan pairs both hormones. Intro pricing that steps up at renewal is common, so read the renewal terms, not just the first month.

Insurance is a separate question with no promises attached. Many plans list generic oral capsules on their formulary, but tiering, quantity limits and prior authorization vary by plan and state, and fertility related or compounded products are frequently excluded. Coverage policy background for women’s health benefits is tracked by KFF’s women’s health policy research. Verify benefits with your own plan before assuming anything. To compare a plan route against paying cash, this calculator does the arithmetic:

A pharmacy cash price and a telehealth program price are not the same product. One is medication only; the other usually bundles the visit, messaging and refills. A worked example of how those layers stack up appears in our Free Savings Report, and other cost estimators sit in the Free Health Calculators collection.

How telehealth programs prescribe it, and what varies

Hormone care by telehealth is now routine, and programs differ more than their homepages suggest. The visit model is the first split: some run a live video consultation with a clinician licensed in your state, others use an asynchronous questionnaire reviewed later. Prescribing rules are set state by state, so availability depends on where you live.

Testing is the second split. Some programs require baseline blood work, some accept recent results from your own doctor, and some prescribe on symptoms and history alone. Neither approach is automatically better, but you should know which one you are buying, and whether lab fees sit inside or outside the monthly price.

Fulfillment is the third. A program may send prescriptions to a retail pharmacy, use a mail order pharmacy for approved products, or route you to a compounding pharmacy for custom preparations. That single detail changes what you receive, what oversight applies, and what it costs.

Follow up is where programs quietly diverge. Ask how often a clinician reviews your regimen, whether unscheduled bleeding triggers evaluation, who answers questions between visits, and how cancellation works. Programs that prescribe hormone therapy are listed in the Telehealth Provider Directory, and the criteria behind the ratings you see are set out on the How We Score Providers page.

Questions worth asking before you start

Walking in with a short list changes the conversation. These are the ones that tend to surface what matters:

• Which approved product and form are you prescribing, and why that one for me?
• Is this being prescribed for a labeled use, or off label? What does the evidence show?
• Given my history of clots, heart disease, breast cancer, liver problems or migraine, what are my specific risks?
• Do the capsules contain peanut oil, and does that matter for me?
• Which of my current medicines and supplements could interact?
• What side effects should I expect early, and which mean I should call?
• How will we monitor this, and when do we reassess whether to continue?
• Is this compounded? If so, which pharmacy, and what testing does it do?
• What exactly does the monthly price include, and what changes at renewal?

One more point on bleeding: any new or unexplained vaginal bleeding after menopause needs evaluation, and hormone therapy does not remove that rule. Do not assume it is just the medicine.

Authoritative sources

These references stay current and go deeper than any summary can:

• Product labeling, including the boxed warning and full contraindication list, on DailyMed from the National Library of Medicine.
• Patient level drug information from MedlinePlus, the NIH consumer health service.
• Regulator guidance on menopause treatments in the FDA’s consumer publication on menopause medicines.

Educational content, not medical advice. Always consult a qualified clinician before starting, stopping or switching treatment.