Crinone

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Crinone

Property Description
Active ingredient Micronized Progesterone
Form Vaginal Gel
Pharmacological class Progestogen (Steroid Hormone)
General Purpose Hormone Restoration/Supplementation
Origin Bio-identical

What is Crinone and Its Chemical Identity?

Crinone is a prescription-only pharmaceutical preparation whose active ingredient is micronized progesterone. It is officially classified as a progestogen, placing it within the broader category of steroid hormones. Progesterone is a hormone that plays a critical role in the menstrual cycle and the maintenance of pregnancy.

This medicine is a single-ingredient product designed to supplement natural hormone levels. The progesterone it contains is often described as bio-identical because its chemical structure is exactly the same as the sex hormone produced endogenously by the human body. As a progestogen, its role is defined by its ability to bind to and activate specific progesterone receptors, initiating a necessary hormonal effect in the female reproductive system. This specific hormonal support is clinically recognized for balancing reproductive system conditions dependent on adequate progesterone levels.


Composition: A Vaginal Gel Delivery System

The dosage form of Crinone is a specialized, aqueous-based vaginal gel intended for vaginal administration, which is a distinctive feature of this brand.

This unique form is key to the drug's action, utilizing a proprietary bioadhesive polymer delivery system that allows the micronized progesterone to adhere to the vaginal lining. This targeted delivery facilitates efficient absorption of the active ingredient into the bloodstream. This drug delivery system allows for sustained progesterone levels in the body over 24 hours. Unlike other progestogen administration methods, the vaginal gel provides a focused route of administration, helping to ensure a consistent and sustained release of the hormone.


What is the General Purpose of This Progestogen?

The general purpose of Crinone is to provide hormone restoration or supplementation to maintain adequate levels of progesterone in the body.

By supplying this essential progestogen, the medicine supports key biological conditions that are dependent upon sufficient progesterone signaling for balance and maintenance. Its physiological action ensures that the critical molecular pathways regulated by the steroid hormone are activated, supporting the necessary biological environment for the body's natural processes, such as supporting the uterine lining in women requiring hormonal assistance.

Regulatory References

  1. MedlinePlus

What side effects are possible with Crinone?

The official safety profile for Crinone (micronized progesterone vaginal gel) communicates the spectrum of documented adverse reactions and high-level safety constraints as categorized by governmental regulatory authorities.

Frequency-Classified Adverse Reactions

Adverse reactions are classified based on their observed incidence in clinical use:

  • Common (may affect up to 1 in 10 users): These effects include headache, somnolence (drowsiness), fatigue, and hot flushes. Localized effects such as breast tenderness or pain, vaginal discharge, and perineal pain are also listed as common.
  • Uncommon: Lower-frequency effects include changes in mood (including depressed mood), as well as gastrointestinal effects such as vomiting, abdominal distension, diarrhea, and constipation.
  • Not Known: This category includes effects for which frequency cannot be accurately estimated from available data, such as hypersensitivity reactions (e.g., urticaria/hives and rash).

Serious Adverse Reactions and Safety Constraints

The regulatory label includes specific warnings concerning serious events known to be associated with steroid hormone treatments, including progestogens. These events include the potential for Thromboembolic Events (TEE), such as Deep Vein Thrombosis (DVT), Pulmonary Embolism (PE), Stroke, and Myocardial Infarction. Treatment may also need to be discontinued if acute ocular events occur, as specified in regulatory documentation.

Safety constraints define specific patient conditions where Crinone is contraindicated. This medicine must not be used in individuals with severe hepatic impairment, a known or suspected hormone-sensitive malignancy, or undiagnosed vaginal bleeding until the cause is investigated. Caution is advised in patients with conditions that may be aggravated by fluid retention, such as epilepsy or asthma.

Overdose and Emergency Response

Overdose and when to seek help

The following information is based strictly on official government regulatory documents (e.g., FDA and EMA) concerning acute over-exposure to Crinone (micronized progesterone vaginal gel).


Documented Overdose Manifestations

Classification Manifestation
Central Nervous System (CNS) Drowsiness, dizziness, fatigue
Gastrointestinal (GI) Nausea, vomiting

Overdosage with progesterone products is associated with clinical signs of excessive systemic exposure to the progestogen. Official regulatory information states that acute overdosage is generally not anticipated due to the specific vaginal gel formulation. However, the documented manifestations of over-exposure are consistent with these signs of CNS and GI effects.


Emergency Action and Treatment Protocol

In the event of a suspected or known acute overdose, the official regulatory guidance mandates that individuals seek immediate medical attention and contact emergency services.

Management Aspect Regulatory Statement
Antidote No specific antidote is known for progesterone overdose.
Treatment Management is limited to symptomatic and supportive treatment.
Monitoring Hospital monitoring may be required in cases of significant over-exposure or persistent documented symptoms.

Due to the lack of a specific antidote, the regulatory requirement is to ensure prompt medical assessment and the application of supportive care to manage any symptoms arising from the over-exposure.

Therapeutic Uses of Crinone

What Crinone Treats: Main Uses and Benefits

Crinone (progesterone gel) is a form of the hormone progesterone and may be part of symptomatic management in certain reproductive and hormonal conditions. It is used to provide progesterone supplementation.

The medicine is primarily indicated for two distinct therapeutic domains: progesterone supplementation as part of Assisted Reproductive Technology (ART) and the treatment of secondary amenorrhea. When applied in these settings, Crinone is commonly used across conditions presenting with acute episodes to address symptoms related to systemic imbalance.

In clinical scenarios, Crinone may assist with supportive relief when used in contexts involving heightened systemic burden, providing benefit to patients. The use of Crinone helps address symptom clusters that may become intense or disruptive, especially those symptoms linked to organ-specific functional stress. The treatment supports functional stability during symptomatic phases.

“The application is relevant when supportive symptom management is appropriate and contributes to easing the overall symptom load.”

For individuals dealing with the temporary disruption of absent menstrual periods, progesterone supplementation assists with maintaining functional stability and contributes to improved comfort during symptomatic periods, helping patients cope more steadily.

Quick Fact: Relief for symptoms related to physical discomfort.

Eligibility and Restrictions for Use

Crinone is officially indicated for adult women of reproductive age for progesterone supplementation in Assisted Reproductive Technology (ART) and for the treatment of secondary amenorrhea.

Contraindicated Populations

The medicine must not be used by individuals with specific medical conditions, as listed in the regulatory labeling:

  • Known hypersensitivity to progesterone or any gel ingredients.
  • Known or suspected malignancy of the breast or genital organs.
  • Current or history of thromboembolic disorders (e.g., deep vein thrombosis, pulmonary embolism).
  • Severe hepatic dysfunction or liver disease.
  • Undiagnosed vaginal bleeding or known retained missed abortion.
  • Acute porphyria.

Age and Conditional Use Status

Category Official Regulatory Classification
Pediatric Use Not indicated; safety and effectiveness not established.
Geriatric Use Not indicated; no data available for this population.
Pregnancy Status Permitted for use in early pregnancy for luteal phase support in ART.
Lactation Status Not recommended during breastfeeding.

Use requires careful observation in patients with a history of depression, or conditions aggravated by fluid retention, such as cardiac or renal dysfunction.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Crinone is primarily defined by administration constraints related to its specialized vaginal gel formulation and a limited systemic interaction scope, as documented by authorities like the FDA and EMA.

Local Administration and Timing Constraints

The most important interaction constraint involves physical interference with the gel’s bioadhesive delivery system. Crinone is not recommended for use concurrently with other local intravaginal therapy or preparations. This restriction applies to any substance or medicine intended for vaginal application. To prevent physical interference and ensure proper absorption, administration of Crinone and any other local intravaginal therapy must be separated by an interval of at least 6 hours, a mandatory timing rule established in regulatory documents.

Systemic Metabolic Considerations

Formal drug-drug interaction studies with Crinone vaginal gel have not been widely performed. However, regulatory sources address potential metabolic interactions involving the CYP3A enzyme system, which are known to affect oral progestogens. Official labeling explicitly states that co-administration with CYP3A inducers (a category of substances that can accelerate drug metabolism) is not expected to result in significant consequences on the progesterone plasma levels achieved with the vaginal gel formulation. No other specific systemic medicines, food, alcohol, or herbal products are documented as having clinically significant interactions.

Mechanism of Action

Crinone delivers progesterone, a steroid hormone, which acts as a direct agonist of the intracellular progesterone receptor (PR), existing as isoforms PR-A and PR-B, in target cells. Following rapid passive diffusion across the cell membrane, progesterone binds to the PR, causing dissociation of heat shock proteins and subsequent receptor dimerization. The activated, dimeric PR complex translocates to the nucleus and functions as a ligand-activated transcription factor.

This complex recognizes and binds to specific Progesterone Response Elements (PREs) in the promoter regions of target genes, thereby modulating their gene transcription. This leads to altered synthesis of specific regulatory proteins. The key intracellular consequence in the endometrium is the suppression of estrogen-driven proliferation and the induction of glandular development, secretory activity, and increased vascularization, representing a transition to a secretory state. This tissue-level modification constitutes the primary system-level physiological consequence of PR agonism.

Dosage and Administration Information

Official Administration Guidelines

Crinone (progesterone gel) is a pharmaceutical preparation delivered exclusively via the intravaginal route. The medication is available in prefilled, single-use applicators at two primary strengths: a 4% concentration, delivering 45 milligrams (mg) of micronized progesterone, and an 8% concentration, delivering 90 mg of the active ingredient.


Labeled Dosing Regimens and Duration

The specific dosage and treatment duration are defined by the therapeutic context:

Context Strength and Frequency Course Duration
Assisted Reproductive Technology (ART) 90 mg (8% gel) once daily Continued for up to 10 to 12 weeks of gestation
Secondary Amenorrhea 45 mg (4% gel) or 90 mg (8% gel) every other day Administered for a short, defined course of six doses

Procedural and Timing Instructions

For procedural clarity, the gel is administered using the supplied single-use applicator, which should be shaken to ensure the gel is ready for application. While administration is often performed at bedtime, consistent timing is key for the prescribed regimen. A mandatory procedural instruction is the constraint on concurrent use: the administration of Crinone must be separated from any other vaginal products by a minimum interval of six hours to maintain the integrity of the bioadhesive delivery system. If a dose is missed, it should be administered as soon as the patient remembers, and the regular schedule should then be resumed.

Recent Clinical Evidence

Research evidence / Overview of Studies for Crinone

This section provides a summary of the clinical studies and available research for Crinone, detailing the types of research conducted, the outcomes monitored, and what remains uncertain in the evidence landscape. This information is intended for educational purposes only and is not medical guidance.


Evidence for Use in Assisted Reproductive Technology (ART)

The majority of clinical research involving this medicine is related to progesterone supplementation during Assisted Reproductive Technology (ART) procedures, such as in vitro fertilization (IVF). This research primarily focused on examining the effects of progesterone administration on the uterine lining in women who are undergoing these treatments.

Researchers in these studies primarily focused on measuring definitive clinical outcomes, including Clinical Pregnancy Rate, Ongoing Pregnancy Rate, and Live Birth Rate. Study populations were infertile women of reproductive age undergoing ART, including those requiring full progesterone replacement (such as women receiving donor oocytes).

Findings described patterns observed in the studies, reporting that the measured outcomes related to live birth and ongoing pregnancy were observed across the different forms of progesterone examined for ART support. Research described that the vaginal delivery system was associated with the progestational transformation in the uterine lining that researchers were monitoring.


Evidence for Use in Secondary Amenorrhea

Research was studied for use in the context of secondary amenorrhea, which refers to the absence of menstrual periods. These studies were often conducted as open-label trials to evaluate the expected physiological response.

The primary measures researchers examined were the incidence of withdrawal bleeding and the progestational transformation of the endometrial lining. Studies focused on women with secondary amenorrhea who had already been estrogen-primed. Studies monitored the incidence of withdrawal bleeding, reporting that most participants were observed to have this outcome following the medicine's administration schedule.


Research Gaps and Uncertainties

One key limitation in the broader evidence landscape is that many of the follow-up durations were limited in the pivotal efficacy trials, with primary endpoints often measured within the first trimester of pregnancy. Furthermore, comparative evidence is lacking for all possible different routes and frequencies of progesterone administration. Data for certain groups, particularly concerning the full long-term functional outcomes for women and children beyond the immediate post-delivery period, remain insufficient and continue to be a subject of broader research in reproductive medicine.

Frequently Asked Questions (FAQ)

Common questions about Crinone (FAQ)

Q: Is it normal to have discharge or residue when using Crinone?

A: Yes, according to patient information, it is common to notice a white discharge or small globules of gel residue. This is due to the remaining gel accumulating on the vaginal wall. Official product information indicates that this residue does not affect the amount of progesterone absorbed by the body.


Q: How quickly does Crinone start working after the first application?

A: Crinone is designed as a sustained-release gel to provide prolonged progesterone absorption. Pharmacokinetic studies indicate that stable plasma concentrations of the hormone, known as steady-state, are typically achieved within the first 24 hours after treatment begins.


Q: Why is progesterone needed during certain stages of fertility treatment?

A: Progesterone is a naturally occurring hormone that plays a key role in supporting early pregnancy. When used during fertility treatment, it helps cause the lining of the uterus to transition into a secretory state. This modified environment is part of the biological process that is associated with supporting the successful implantation and maintenance of a fertilized egg.


Q: What does the term 'luteal phase support' mean in relation to Crinone?

A: Luteal phase support is a medical term that describes the use of a progesterone product, like Crinone, during the second half of the menstrual cycle. This hormone supplementation is done as part of an Assisted Reproductive Technology (ART) procedure to help maintain the lining of the uterus and support a pregnancy.


Q: What kinds of symptoms might indicate that Crinone is not being tolerated well?

A: Official warnings advise patients to seek immediate medical attention for symptoms that signal a potential blood clot or serious event. These warning signs include: sudden severe headache, dizziness or faintness, problems with vision or speech, sudden weakness or numbness of an arm or leg, or severe pain in the calves or chest. Discontinuation is required if such events are suspected.


Q: What is the role of Crinone in hormone replacement therapy, if any?

A: Crinone is officially indicated for progesterone supplementation in Assisted Reproductive Technology and for the treatment of secondary amenorrhea (the absence of menstrual periods). Some clinical references indicate that the 4% strength has been used in combination with estrogen for certain menopause-related hormone regimens.


Q: Are there reports of Crinone causing abdominal pain or cramping?

A: Yes, according to official adverse reaction data, both abdominal pain and cramping are listed among the commonly reported side effects experienced by users of Crinone.


Q: Is there research on Crinone's effectiveness in preventing early miscarriage?

A: The official regulatory labeling explicitly addresses this topic. It states that there is no adequate evidence available to show that progesterone products are effective for preventing miscarriage in women with a history of recurrent spontaneous pregnancy losses.


Q: Is Crinone the same kind of medication as Prometrium?

A: Both Crinone and Prometrium contain the same active ingredient, which is micronized progesterone. However, Crinone is an official formulation of a vaginal gel, while Prometrium is an official formulation of an oral capsule.


Q: What is the consistency of the gel like?

A: Crinone is a specialized formulation described in the official product information as a soft, white to off-white bioadhesive gel. The gel contains a polymer system designed to stick to the vaginal wall for sustained hormone delivery.


Q: What does official guidance say about discontinuing Crinone?

A: Official guidance advises that treatment should be stopped immediately if the earliest signs or symptoms of a potential blood clot or an acute ocular (eye-related) event occur or are suspected. The decision to stop the medicine outside of these warnings is determined by the prescribing healthcare provider.


Q: What are the main differences between a vaginal gel like Crinone and progesterone suppositories?

A: Crinone is a bioadhesive vaginal gel in a prefilled applicator that is formulated to provide a sustained release of progesterone over time. Other vaginal progesterone forms, such as suppositories, may have different absorption characteristics, delivery properties, or dosing schedules.


Q: Does Crinone affect blood sugar levels, according to regulatory documents?

A: Official regulatory documents do not state a direct effect of Crinone on blood sugar levels. However, the label does advise that special attention should be paid to the care of patients with conditions like diabetes while they are using the medication.


Q: How is Crinone typically supplied (e.g., how many applications come in a box)?

A: Crinone is supplied in cartons that hold prefilled, single-use applicators. According to the official supply information, common quantities include 6 or 15 applicators per box.


Q: How does the absorption of Crinone gel compare to oral progesterone pills?

A: Official studies indicate that vaginal administration of the gel provides greater bioavailability (the amount of the drug that reaches the bloodstream) compared to taking progesterone as an oral capsule. It also shows less variability in absorption between individuals.

How should Crinone be stored and disposed of?

How to Store and Dispose of Crinone — Official Regulatory Information

The storage of Crinone (progesterone gel) must adhere to label specifications to maintain stability. Disposal must follow strict pharmaceutical waste guidelines.

Item Official Regulatory Statement
Storage Temperature Store at controlled room temperature, specifically 20^circ to 25 C (68^circ to 77 F); Do not store above 25 C and Do not freeze
Stability / Handling Each applicator is for single use only. Any unused gel must be discarded immediately after use.
Child Safety Keep out of the sight and reach of children.
Disposal Instructions Dispose of unused product or waste material in accordance with local requirements. Do not throw away medicines via wastewater or household waste.

Regulatory documents define that the product must be stored within a specific temperature range to prevent degradation and must be kept out of the reach of children for safety. Since the applicator is single-use, any contents remaining after the administration of the dose must be discarded. Final disposal of expired or unused medicine must adhere to local environmental protocols.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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