Utrogestan (Progesterone)
Is It Right for You?
A complete guide to Utrogestan (Progesterone) — what it treats, how it works, dosages, side effects, and when a clinician may prescribe it following an online consultation.
What is Utrogestan (Progesterone)?
Utrogestan is a brand of micronised progesterone — a bioidentical (also called body-identical) form of progesterone, chemically identical to the progesterone naturally produced by the human body. It is manufactured by Besins Healthcare and is available in 100 mg and 200 mg soft capsule formulations. Utrogestan is licensed in the UK both as an oral capsule (taken by mouth) and for vaginal use (the capsule is inserted vaginally, an off-label but widely practised route that produces different pharmacokinetics and a distinct side effect profile).
The term "micronised" refers to the manufacturing process in which progesterone particles are ground to extremely small sizes, dramatically improving oral bioavailability. Unmicronised progesterone is poorly absorbed from the gastrointestinal tract; micronisation overcomes this barrier and makes oral administration clinically viable.
Utrogestan is used primarily in the context of hormone replacement therapy (HRT) as the progestogen component for women with a uterus. It is also used in fertility medicine to support luteal phase function during assisted conception, in threatened or recurrent miscarriage, and in the treatment of various gynaecological conditions. It represents one of the most widely prescribed HRT progestogens in the UK, particularly following the increased demand for body-identical HRT driven by updated NICE guidance (NG23, 2015, updated 2024) and widespread public discussion of menopause management.
Utrogestan should be distinguished from synthetic progestogens (progestins) such as norethisterone, medroxyprogesterone acetate, and levonorgestrel, which are structurally distinct from natural progesterone and have different receptor binding profiles, side effect patterns, and risk considerations.
What Conditions Does Utrogestan Treat?
Utrogestan is prescribed for:
While Utrogestan is essential for endometrial protection in women using oestrogen-based HRT, it does not provide the benefits of oestrogen and should be used in conjunction with it.
How Does Utrogestan Work?
Progesterone exerts its effects by binding to intracellular progesterone receptors (PR-A and PR-B) present in the uterus, breast, brain, cardiovascular system, and other tissues. The progesterone-receptor complex then modulates gene transcription, producing tissue-specific effects.
In the uterus, progesterone counteracts the proliferative effects of oestrogen by inducing secretory transformation of the endometrium, reducing mitotic activity of endometrial cells, and promoting decidualisation — the preparation of the uterine lining for potential implantation. These actions are the basis of progesterone's role in endometrial protection during HRT and luteal phase support in fertility.
In the brain, progesterone and its neuroactive metabolite allopregnanolone act on GABA-A receptors, producing anxiolytic, sedative, and sleep-promoting effects. This neurosteroid activity is responsible for the drowsiness some women experience with oral Utrogestan and also underlies its well-documented sleep-quality benefit when taken orally at bedtime. This same mechanism means that, unlike many synthetic progestins, natural micronised progesterone has a neutral or positive effect on mood in most women — an important distinction from older progestogens that can cause mood-related side effects.
Compared with synthetic progestins, natural progesterone has a more selective receptor binding profile — it does not significantly bind androgen, glucocorticoid, or mineralocorticoid receptors, which means it avoids the acne, fluid retention, and mood-lowering effects associated with androgenic progestins such as norethisterone.
Dosages & Administration
The correct dose depends on the type and severity of infection, age, weight, and kidney function. Always follow your clinician's instructions. The table below is for general reference only.
Administration Tips
Oral Utrogestan capsules should always be taken at bedtime with a small amount of water, and ideally with a small snack or light meal — fat in the stomach increases progesterone absorption. The drowsiness effect, while sometimes inconvenient, becomes a benefit when the capsule is taken at night, as many women on Utrogestan report significantly improved sleep quality. Capsules should not be chewed or broken.
For vaginal use: the capsule is inserted as far back into the vagina as comfortable, ideally at bedtime to minimise leakage. Some patients find a panty liner helpful. The waxy capsule shell will dissolve and a small amount of white discharge is normal.
Side Effects of Utrogestan
Utrogestan is generally well tolerated, but some side effects may occur.
- Drowsiness and sedation: The most commonly reported side effect, resulting from the neurosteroid activity of progesterone and allopregnanolone on GABA-A receptors. Taking the capsule at bedtime mitigates this and often converts it into a therapeutic benefit (improved sleep).
- Dizziness: May occur, particularly at onset of treatment; usually settles.
- Headache: Reported by some women; often settles with continued use.
- Breast tenderness or fullness
- Nausea: Less common; usually taking the capsule with a small snack reduces this.
- Mood changes: Most women report neutral to positive mood effects with micronised progesterone, distinguishing it favourably from many synthetic progestins. A small number of women report worsening mood, anxiety, or low mood, likely related to individual sensitivity to neurosteroid fluctuations.
- Irregular bleeding or spotting: Common during the first 3–6 months of continuous combined HRT as the endometrium transitions to atrophy. Persistent or heavy irregular bleeding after 6 months warrants investigation.
- Vaginal discharge: If capsules are used vaginally, a white chalky discharge from the dissolving capsule shell is expected and normal.
- Venous thromboembolism (VTE): Unlike synthetic progestins (particularly oral medroxyprogesterone acetate), observational data from large studies (including the French E3N cohort) suggest that micronised progesterone does not significantly increase VTE risk when used with transdermal oestradiol. This is in contrast to combined oral HRT with synthetic progestins. This favourable VTE profile is one of the major clinical advantages of Utrogestan within HRT regimens.
- Breast cancer: All combined HRT (oestrogen plus progestogen) carries some associated breast cancer risk. Current evidence suggests that micronised progesterone may be associated with a lower breast cancer risk than synthetic progestins, though risk increases with duration of use and is still present. The absolute risk for most women is small and should be contextualised against the benefits of HRT. This is an active area of research and guidelines are updated periodically.
- Allergic reactions: Rare; including rash, urticaria, and anaphylaxis.
- Cholestatic jaundice: Rare adverse effect reported with progesterone; discontinue if jaundice develops.
Patients should be aware of the potential for drowsiness and should avoid driving or operating machinery after taking Utrogestan.
Drug Interactions
Always disclose all prescription drugs, over-the-counter medicines, vitamins, and supplements to your clinician or pharmacist before starting Utrogestan
(e.g. Rifampicin, Carbamazepine, Phenytoin, Phenobarbital, St John’s Wort) — May increase the metabolism of progesterone, reducing its effectiveness. Dose adjustment or alternative therapy may be required.
(e.g. Ketoconazole, Itraconazole, Clarithromycin) — May increase progesterone levels, potentially enhancing side effects such as drowsiness or dizziness. Monitor for tolerability.
Important Warnings
Oral Utrogestan causes drowsiness. Patients must not drive or operate machinery after taking oral doses. Always take at bedtime.
Alcohol enhances the sedative effects of oral progesterone. Avoid alcohol on evenings when Utrogestan is taken.
Irregular or unexpected vaginal bleeding during HRT requires clinical assessment to exclude endometrial pathology. Do not ignore persistent or heavy unexpected bleeding.
Utrogestan contains arachis oil and soya lecithin. It must not be used in patients with known peanut or soya allergy. Always check allergy status before prescribing.
Speak to a Clinician About Treatment
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The treatment you need, when you need it.
Utrogestan FAQs
Oestrogen stimulates growth of the endometrium (uterine lining). In women with an intact uterus, unopposed oestrogen causes progressive endometrial proliferation which, over time, can lead to hyperplasia and endometrial cancer. Adding progesterone (or a synthetic progestogen) counteracts this effect, inducing secretory changes and regular shedding or atrophy of the endometrium, depending on the regimen used. Women who have had a hysterectomy do not have an endometrium and therefore do not need progestogen.
Yes. Vaginal administration is a widely used route, particularly for women who find oral Utrogestan too sedating or who experience other oral side effects. The vaginal route produces high local uterine concentrations with lower systemic levels, substantially reducing the sedative and other systemic effects. While this route is off-label for HRT in the UK, it is well-recognised in clinical practice and supported by published guidance. Your clinician can advise whether this is appropriate for you.
For most women, oral Utrogestan taken at bedtime improves sleep quality. The neurosteroid activity of progesterone and its metabolite allopregnanolone on GABA-A receptors produces a sedative, calming effect that many women find genuinely beneficial, particularly in the context of menopause-related sleep disruption. This is one of the most consistently reported positive effects of micronised progesterone versus synthetic progestins.
No. The Mirena intrauterine system (IUS) delivers the synthetic progestogen levonorgestrel directly to the uterus and is an alternative way to provide endometrial protection for HRT. Utrogestan contains natural progesterone and is taken orally or vaginally. Both approaches are effective for endometrial protection; the choice depends on patient preference, medical history, and clinical suitability.
Weight gain is more commonly associated with synthetic androgenic progestins (such as norethisterone) than with micronised progesterone. Utrogestan's receptor selectivity means it does not significantly activate androgenic or glucocorticoid pathways. Most women do not experience weight gain attributable to Utrogestan, though changes in body composition during the menopause transition itself are common regardless of HRT type.
This is a complex and evolving area. Standard guidance currently recommends that HRT is generally contraindicated following hormone receptor-positive breast cancer. Some specialist breast oncology teams may consider micronised progesterone in carefully selected patients as part of shared decision-making, given its potentially more favourable breast safety profile compared with synthetic progestins. This must be managed by a specialist with relevant experience and following full informed consent. Do not start or continue Utrogestan after a breast cancer diagnosis without specialist review.
If you miss a dose of Utrogestan within a cyclical HRT regimen, take it as soon as you remember, unless it is nearly time for the next dose, in which case skip the missed dose. Do not double up. Consistency in taking the full number of days of progestogen per cycle is important for endometrial protection — if you frequently miss doses, discuss this with your clinician.