Overview of Tansy

Property	Description
Active ingredient	Levonorgestrel
Form	Tablet (Oral)
Pharmacological class	Emergency Contraceptive
Common use	Backup method to prevent pregnancy
Origin	Synthetic (Progestin)

What Type of Medication is Tansy?

Tansy is the specific trade name for a single-agent pharmaceutical product classified as an emergency contraceptive (EC), placing it within the broader pharmacological class of hormonal contraception. This medication is explicitly designed as a time-sensitive, backup method to reduce the chance of pregnancy following unprotected sexual intercourse or a known failure of a contraception method. Pharmacological studies consistently demonstrate the high efficacy of its active compound in preventing conception.

Composition and Origin: Levonorgestrel as the Active Ingredient

The active ingredient in Tansy is levonorgestrel, which is a synthetic progestin that is chemically related to the natural hormone progesterone. This is a progestin-only formulation, a key characteristic that sets it apart from combined pills that contain both estrogen and progestin. As an EC, the medication is prepared in an oral dosage form as a tablet, incorporating common inactive excipients like lactose monohydrate.

Defining the Purpose of Emergency Contraception

The core purpose of the levonorgestrel in Tansy is to intervene rapidly in the reproductive cycle to prevent the initiation of pregnancy. The medication is clinically recognized for its ability to primarily prevent or delay ovulation by suppressing the necessary hormonal surge. Because it acts by preventing conception rather than terminating an established pregnancy, it is formally classified as non-abortifacient.

Regulatory References

WHO Essential Medicines List

What side effects are possible with Tansy?

The safety profile of levonorgestrel, the active ingredient in Tansy, is defined by hormonal-related effects documented in official regulatory labeling. These adverse reactions are classified by frequency and grouped by the physiological system affected, following established regulatory standards.

Classification of Officially Documented Adverse Reactions

Very Common Reactions (affecting 1 in 10 people or more) often involve the Nervous System and Gastrointestinal Disorders, and include headache, nausea, lower abdominal pain, and fatigue. Also classified in this tier are bleeding not related to menses.

Common Reactions (affecting between 1 in 100 and 1 in 10 people) include dizziness, diarrhoea, and vomiting. Common effects on the Reproductive System are breast tenderness, irregular menstruation, and a delay of menses greater than seven days from the expected date.

Very Rare Reactions (affecting fewer than 1 in 10,000 people) have been reported, including generalized abdominal pain, rash, urticaria (hives), and face oedema (swelling).

Safety Constraints and Special Considerations

Official labeling defines specific safety constraints. The possibility of an ectopic pregnancy must be considered in any woman who becomes pregnant following use or reports severe lower abdominal pain. The medication is contraindicated if a known or suspected pregnancy exists, as it is not effective for termination. While levonorgestrel is present in breast milk, no significant adverse effects on the infant are generally noted, though cases of decreased milk production have been reported. It is explicitly stated in government guidance that this emergency contraceptive does not provide protection against HIV or other sexually transmitted infections.

Overdose and Emergency Response

Overdose and When to Seek Help

This section outlines the officially documented clinical presentations and mandated emergency actions for Tansy (Levonorgestrel) overdose, based strictly on government regulatory documents.

Documented Overdose Profile

Official regulatory information consistently notes that acute overdose with Levonorgestrel is generally associated with a low risk of serious toxicity.

Domain	Documented Regulatory Statement
Clinical Manifestations	Overdose presentations typically involve nausea, vomiting, and episodes of vaginal bleeding (withdrawal bleeding).
Antidote Availability	Regulatory documents explicitly state that no specific antidote is known for Levonorgestrel.
Management Approach	The mandatory official procedure for overdose is limited to symptomatic and supportive treatment.

Required Emergency Actions

The most important regulatory directive is to seek immediate medical attention for the management of the symptoms. Urgent consultation with a healthcare professional or a Poison Control Center is required when symptoms are severe, unusual, or persistent following the ingestion.

Pediatric Note: Accidental ingestion in children has been noted by authorities, with reported effects generally being mild and not serious.

The regulatory profile defines overdose by its non-life-threatening clinical manifestations, reinforcing that intervention focuses entirely on professional assessment and supportive care, rather than specific antagonistic measures. This underpins the requirement to seek medical help based solely on symptom severity and persistence.

Therapeutic Uses of Tansy

Quick Facts on Traditional Uses

Intestinal Support: Historically used to address intestinal worms and other parasitic infestations.
Skin Applications: Traditional external use includes soothing topical discomforts such as scabies and inflammation.
Insect Management: Applied as an insect repellent and a natural insecticide.

Tansy (Tanacetum vulgare) has an established history in traditional practices, primarily associated with addressing concerns in the digestive and dermatological systems, and as an agent for pest control. The major traditional therapeutic use of Tansy is as an anthelmintic, meaning it has been historically employed to expel intestinal worms and other internal parasites, particularly in children. Due to the presence of certain volatile oils, this use is now often discouraged by health authorities in modern herbal medicine.

In addition to internal use, Tansy has been historically applied externally. The crushed leaves or preparations derived from them were used topically to treat skin conditions like scabies, to allay inflammation, and to relieve joint discomfort and bruises through compresses or poultices. Furthermore, the plant's strong aromatic compounds have made it a common traditional remedy for repelling insects such as flies, fleas, and mites, including its historical use as an insecticide in veterinary practices. Modern studies continue to explore the plant's various traditional applications, including its potential antioxidant, anti-inflammatory, and antimicrobial activities.

Eligibility and Restrictions for Use

Tansy (Levonorgestrel 1.5 mg) is officially indicated for use as emergency contraception in females of reproductive potential. Its eligibility profile is strictly defined by regulatory bodies across three main categories of restriction.

Populations for whom use is Contraindicated

Absolute Contraindications prohibit the use of the medicine if a known or suspected pregnancy exists or if a woman has a known hypersensitivity to levonorgestrel or any component of the tablet. The product is not intended for use as a regular contraceptive method.

Age- and Condition-Based Restrictions

Age-related rules specify that the product is not indicated before menarche (the start of menstruation) and is not intended for use in postmenopausal women. While studies have not identified pediatric-specific safety problems in post-menarcheal adolescents, use is limited to reproductive years.

Conditional restrictions exist for populations with impaired organ function or reduced drug efficacy. The medicine is not recommended in patients with severe hepatic dysfunction. Additionally, regulatory information notes that concurrent use of certain enzyme-inducing medications may decrease the product’s effectiveness. During lactation, the medication is generally considered acceptable.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Pharmacokinetic Interactions

The official regulatory profile for levonorgestrel emergency contraception is primarily defined by pharmacokinetic interactions that can reduce the medication’s exposure in the body. The drug is a substrate for the Cytochrome P450 3A4 (CYP3A4) enzyme system in the liver. Co-administration with enzyme-inducing products is documented to accelerate this metabolism, leading to a significant decrease in levonorgestrel plasma concentrations (AUC).

Interacting Substances

This pharmacokinetic interaction is deemed clinically significant due to the risk of reduced effectiveness. Substances explicitly listed in regulatory documentation that function as enzyme inducers and may decrease levonorgestrel exposure include:

Anticonvulsants/Antiepileptics: Such as Phenytoin, Carbamazepine, Barbiturates, and Primidone.
Antituberculosis Drugs: Including Rifampicin and Rifabutin.
Antifungals: Specifically Griseofulvin.
Antiretroviral Agents: Including Efavirenz and Ritonavir.
Herbal Products: The supplement St. John's Wort (Hypericum perforatum) is documented as a potent enzyme inducer that reduces levonorgestrel levels.

Regulatory Context and Constraints

There are no absolute contraindications listed in the FDA prescribing information based solely on interaction risk for this single-dose product. No formal mandatory timing or separation rules are specified for administration. Regulatory documents note that no formal studies have evaluated the effect of hepatic impairment on the drug's disposition, a population-specific consideration.

Mechanism of Action

How Tansy Works: Mechanism of Action

Tansy, containing levonorgestrel, functions exclusively through the modulation of the female reproductive cycle's core physiology. The mechanism is initiated by the drug acting as a synthetic agonist at the progesterone receptor ( PR). This binding occurs primarily in the hypothalamus and pituitary gland, activating a robust negative feedback loop within the Hypothalamic-Pituitary-Ovarian (HPO) axis.

This central interaction's primary physiological consequence is the suppression or blunting of the Luteinizing Hormone ( LH) surge , the hormonal signal required to trigger follicular rupture. By interfering with this molecular cascade, the drug exhibits the mechanistic consequence of inhibiting or delaying ovulation.

Auxiliary action involves the local binding of levonorgestrel to PR in the cervix, which increases cervical mucus viscosity and thickness. This modulation creates a mechanical barrier that substantially impedes the motility and transport of sperm. It is noted that the mechanism is considered ineffective once ovulation has already occurred and does not interfere with an established pregnancy.

Dosage and Administration Information

Tansy is administered exclusively through the oral route as a tablet. The official prescribing information defines its usage as a single, time-sensitive course of treatment, and it is explicitly designated as not being intended for routine or continuous use as a primary contraceptive method. The standard regimen for adult use involves taking a single tablet containing 1.5 mg of levonorgestrel. Alternatively, a two-dose regimen consisting of two 0.75 mg tablets is also officially documented, where the second dose is taken precisely 12 hours after the first.

A critical instruction is the time constraint: the medication must be taken as soon as possible, and not later than 72 hours after the specific incident for which it is prescribed. The tablet may be administered with or without food. Administration guidance also addresses potential absorption issues: if vomiting occurs within two to three hours after taking any dose, a repeat dose is required. Furthermore, a specific dose modification exists for women concurrently taking certain hepatic enzyme-inducing drugs, where an increased total dose of 3 mg may be considered. These instructions structure the medication's use as an immediate, non-recurring intervention.

Recent Clinical Evidence

Tansy (***Tanacetum vulgare*): Recent Clinical Evidence**

The Common Tansy plant (Tanacetum vulgare) has been historically referenced in traditional medicine; however, its use is widely discouraged by modern regulatory bodies and public health advisories due to safety concerns. There is a lack of sufficient, high-quality clinical evidence to rate the effectiveness of Tansy for any medicinal use, including historical applications for spasms, fevers, or to stimulate menstruation.

Regulatory and Safety Status

Preparations containing the Tansy plant are considered unsafe for internal consumption. This is due to the presence of thujone and other hepatotoxic pyrrolizidine alkaloids (PAs), which carry a risk of severe liver damage, nervous system toxicity, and adverse effects, including convulsions, even in small doses. This is a critical factor in the assessment of any evidence related to the plant.

Summary of Research Findings

Modern research is primarily focused on the plant's constituents and traditional uses. No definitive clinical trials demonstrate the efficacy of ingested Tansy for human health conditions.

Research Focus	Study Type & Results	Caution
Antiparasitic Activity	In vitro (test-tube) studies showed that volatile oils, including thujone, may affect parasitic worms.	Internal use is highly toxic. Safer alternatives are available.
Anti-inflammatory	Laboratory models and animal studies have investigated compounds like parthenin for anti-inflammatory effects.	These findings are not transferable to human treatment recommendations.
Topical Use	Traditionally used as an external application for joint discomfort and insect repellent. The absorption of toxic PAs through broken skin is a serious risk.	Use is generally advised against unless certified PA-free.

Due to the significant and well-documented toxicity profile, the risk of use is widely considered to outweigh any potential, unproven benefits. Consultation with a healthcare provider is essential before considering any herbal preparation.

Frequently Asked Questions (FAQ)

Common questions about Tansy (FAQ)

Q: Is Tansy a type of antibiotic?

A: No, Tansy contains the active ingredient levonorgestrel, which is a synthetic progestogen. It is not an antibiotic. Its official function is to work on hormones to modulate the female reproductive cycle.

Q: Does Tansy have a generic version available?

A: Yes, levonorgestrel 1.5 mg, the active ingredient in Tansy, is available from various manufacturers as generic products. These products are officially regulated under the same standards for safety and effectiveness.

Q: What should I do if I miss a dose of Tansy?

A: The single-dose regimen is complete after one tablet is taken. If the two-dose regimen is used, regulatory instructions state that the second dose must be completed as soon as possible. Official guidance notes that the product's documented efficacy is dependent on administration within the 72-hour window.

Q: Can Tansy cause difficulty sleeping?

A: Official product information lists common side effects that affect the nervous system, including fatigue and headache. Difficulty sleeping (insomnia) is not explicitly listed as a common or very common reaction in the medicine's safety profile.

Q: Are there any long-term side effects associated with Tansy use?

A: Tansy is designed for a single, non-recurring use as an emergency intervention. Official sources describe the medicine's side effects as temporary, and long-term adverse health effects are not commonly reported with its occasional use.

Q: Are there known interactions between Tansy and alcohol?

A: Official regulatory documents do not list a known harmful interaction between levonorgestrel and alcohol. However, alcohol consumption may potentially worsen some of the medicine's temporary side effects, such as nausea or dizziness.

Q: Can Tansy be used by children?

A: Official prescribing information indicates the drug is for use in postmenarchal females (those who have started menstruating). Eligibility may vary by country; in the United States, it is available over-the-counter for women age 17 and older, and by prescription only for those younger than 17.

Q: What if I have kidney issues? Can I still use Tansy?

A: Official regulatory information states that no formal studies have been conducted to evaluate the effect of kidney (renal) impairment on the disposition of levonorgestrel. This type of population-specific information is included in the official label.

Q: What does official information state about Tansy and pregnancy?

A: Tansy is explicitly contraindicated (should not be used) if a known or suspected pregnancy exists. However, official sources indicate that if the medication is accidentally taken when a pregnancy is already established, it is not known to harm the existing pregnancy or the fetus.

Q: What does the research say about Tansy's long-term effectiveness?

A: Official product information confirms that Tansy is an emergency contraceptive intended for use after a single incident. It is not intended or designed to be used as a routine or long-term form of contraception.

Q: Why are there different strengths or dosages of Tansy available?

A: Official regulatory information documents two approved treatment regimens: a single 1.5 mg tablet, and a two-dose regimen of two 0.75 mg tablets taken 12 hours apart. The single 1.5 mg dose is now the most commonly documented and used approach.

Q: Will Tansy make me feel tired or drowsy?

A: Official product information lists headache, fatigue, and dizziness as the most common side effects affecting the nervous system. Drowsiness is not specifically listed among the most frequently reported adverse reactions.

Q: Is Tansy a controlled substance?

A: Regulatory documents state that levonorgestrel is officially classified as not a controlled substance. This means its distribution and use are regulated differently than narcotics or other habit-forming drugs.

Q: What is the risk of dependence or withdrawal with Tansy?

A: Since levonorgestrel is not a controlled substance, official regulatory documents indicate that no information about dependence or withdrawal associated with the use of the emergency contraceptive has been reported.

Q: What happens if I stop taking Tansy suddenly?

A: The full course of treatment is defined by taking the required dose(s) within the 72-hour timeframe. Regulatory guidance notes that if a dose is not fully absorbed, such as if vomiting occurs within two to three hours after taking it, a repeat dose may be considered.

Q: Can Tansy be used by older adults?

A: Tansy is indicated for postmenarchal females and functions as an emergency contraceptive to prevent pregnancy. Older adults are not part of the patient population for whom this medicine is intended or studied.

Q: Are there different forms of Tansy, like tablets versus capsules?

A: The official prescribing information defines Tansy as being administered exclusively through the oral route as a tablet. Other forms, such as capsules, are not described in the product's official instructions.

Q: Is Tansy the same as the herbal supplement Tansy?

A: No, they are distinct products. The drug Tansy contains the hormone levonorgestrel. The herbal supplement, Common Tansy (Tanacetum vulgare), is a plant whose internal consumption is generally advised against by regulatory bodies due to potential toxicity.

Q: Does Tansy affect blood pressure?

A: Tansy is a progestin-only emergency contraceptive. Official labeling does not list high blood pressure as a common adverse reaction for this single-use product. The cardiovascular risks typically associated with birth control are linked to combined hormonal contraceptives that contain estrogen.

Q: What is the chemical name for the active ingredient in Tansy?

A: The chemical name for the active ingredient, levonorgestrel, is a scientific description used in official documentation: 18,19 -Dinorpregn-4-en-20-yn-3-one-13-ethyl-17-hydroxy-, (17alpha) -(-)-.

Q: What precautions should people with heart conditions take with Tansy?

A: The official regulatory context indicates that this progestin-only product is generally not associated with the cardiovascular risks sometimes linked to combined hormonal contraceptives.

Q: What kind of monitoring (like blood tests) is required when taking Tansy?

A: Official regulatory documents and prescribing information do not specify required routine blood tests or other medical monitoring for the single, emergency use of Tansy.

Q: How long do most people need to stay on Tansy treatment?

A: The medication is officially defined as a single, time-sensitive course of treatment. It is taken once (or in two doses 12 hours apart) and is explicitly stated as not being intended for routine or continuous use.

Q: How does Tansy affect the liver?

A: Official information states that the active ingredient, levonorgestrel, is metabolized (broken down) by the Cytochrome P450 3A4 ( CYP3A4) enzyme system in the liver. Products that increase the activity of this enzyme may lower the drug's exposure, which is why potential interactions are noted.

How should Tansy be stored and disposed of?

Official Storage and Disposal Requirements

This section summarizes the official storage, handling, and disposal requirements as mandated by regulatory documents for products containing Tansy (primarily essential oil).

Storage Conditions

Requirement	Official Statement
Temperature	Store in a cool, well-ventilated place, away from heat, sparks, open flames, and all other ignition sources.
Protection	Keep container tightly closed, protected from light and moisture.
Security	Store locked up and keep out of the reach of children.

Handling and Disposal

The product must be handled in accordance with good industrial hygiene practices. Due to its classification, disposal must be managed as hazardous waste.

Environmental Protection: Avoid release to the environment. Do not dispose of contents or containers into drains, sewage, or waterways.
Disposal Rule: Dispose of the material and its container through an approved waste disposal plant in accordance with all applicable local and national regulations.

Tansy