When You Can't Find Prometrium, You Still Have Options

Being told your pharmacy doesn't have Prometrium in stock is stressful — especially when you depend on it for hormone therapy, menstrual regulation, or fertility treatment. But running into a shortage doesn't mean you have to go without treatment.

Several alternative medications can serve similar purposes. In this guide, we'll explain what Prometrium is, how it works, and walk you through the most common alternatives your doctor might consider if you can't fill your prescription.

What Is Prometrium?

Prometrium is the brand name for micronized Progesterone, a bioidentical hormone that matches the progesterone your body naturally makes. It's available as 100 mg and 200 mg oral capsules, manufactured by Virtus Pharmaceuticals.

Doctors prescribe Prometrium primarily to:

• Protect the uterine lining (endometrium) in postmenopausal women taking estrogen therapy
• Treat secondary amenorrhea — missed periods that aren't caused by pregnancy or menopause

It's also commonly used off-label to support fertility treatments, including IVF. For a deeper look, see our article on what Prometrium is and how it's used.

How Does Prometrium Work?

Prometrium delivers micronized progesterone to your body. Once absorbed, it binds to progesterone receptors in the uterine lining, converting it from a growth phase (proliferative) to a stable, secretory phase. This is essential for:

• Preventing the overgrowth of the uterine lining that estrogen alone can cause
• Triggering a menstrual period in women who have stopped having periods
• Supporting early pregnancy by maintaining the uterine environment

To understand the science in more detail, read how Prometrium works: mechanism of action explained.

Alternatives to Prometrium

If Prometrium or generic Progesterone capsules are unavailable, here are the alternatives your healthcare provider may discuss with you. Never switch medications on your own — always talk to your doctor first.

1. Medroxyprogesterone (Provera)

Medroxyprogesterone, sold under the brand name Provera, is the most commonly prescribed alternative to Prometrium. It's a synthetic progestin — meaning it's lab-made and not structurally identical to your body's own progesterone, but it works on the same receptors.

Used for: Endometrial protection during estrogen therapy, secondary amenorrhea, abnormal uterine bleeding

How it's different: Unlike Prometrium, Provera is a synthetic progestin. Some studies suggest bioidentical progesterone (like Prometrium) may have a more favorable side effect profile, but Provera has decades of clinical data behind it and is widely available.

Availability: Provera and generic Medroxyprogesterone are generally easy to find and very affordable — often under $15 with a discount card.

2. Norethindrone Acetate (Aygestin)

Norethindrone Acetate is another synthetic progestin. It's FDA-approved for treating endometriosis, amenorrhea, and abnormal uterine bleeding.

Used for: Endometriosis, amenorrhea, abnormal uterine bleeding, and sometimes as part of HRT

How it's different: Norethindrone is a different type of synthetic progestin than Medroxyprogesterone. It may be preferred for certain conditions like endometriosis. It's not bioidentical.

Availability: Generic Norethindrone Acetate is generally available and affordable.

3. Endometrin (Vaginal Progesterone Insert)

Endometrin is a vaginal insert that delivers progesterone directly to the uterus. It contains 100 mg of progesterone per insert and is FDA-approved specifically for luteal phase support in fertility treatments.

Used for: Luteal phase support during assisted reproductive technology (ART) procedures like IVF

How it's different: Unlike Prometrium capsules, Endometrin is inserted vaginally. This delivers progesterone more directly to the uterus and may cause less drowsiness and dizziness than oral Prometrium. However, it's not typically used for general HRT or amenorrhea.

Availability: Endometrin is a specialty product, often dispensed through fertility clinic pharmacies. It's more expensive than generic oral Progesterone.

4. Compounded Progesterone

If commercial Progesterone products are unavailable, a compounding pharmacy can prepare custom progesterone formulations — capsules, creams, troches, or suppositories — tailored to your prescription.

Used for: Any indication where progesterone is needed, when commercial products are unavailable

How it's different: Compounded products are not FDA-approved and are not subject to the same manufacturing standards as commercial medications. However, they can be a valuable option during shortages. Make sure to use a reputable compounding pharmacy, ideally one accredited by the Pharmacy Compounding Accreditation Board (PCAB).

Availability: Generally available through compounding pharmacies. Your doctor will need to write a specific prescription. Cost varies but is often $30 to $90 per month.

How to Decide Which Alternative Is Right for You

The best alternative depends on why you're taking Prometrium:

• For HRT/endometrial protection: Medroxyprogesterone (Provera) is the most direct substitute and is widely available.
• For fertility/IVF support: Endometrin or compounded progesterone suppositories are commonly used.
• For amenorrhea: Either Medroxyprogesterone or Norethindrone Acetate may work.
• If you strongly prefer bioidentical: Compounded progesterone is likely your best bet during a shortage.

Your doctor and pharmacist can help you weigh the pros and cons based on your specific health needs, insurance coverage, and what's actually available.

Final Thoughts

Not being able to find Prometrium is frustrating, but you're not out of options. Several effective alternatives exist, and your healthcare provider can help you find one that works for your situation.

In the meantime, you can use Medfinder to check whether Prometrium or generic Progesterone has become available at a pharmacy near you. You can also explore ways to save money on Prometrium when you do find it.