Samyr

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Medically reviewed

Laura Arias

Last updated on 22/12/2025

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 Samyr

What is Samyr? Defining the Active Ingredient (Ademetionine)

Property Description
Active ingredient Ademetionine (S-adenosyl-L-methionine, SAMe)
Form Enteric-coated tablets; Powder for solution (for injection)
Pharmacological class Amino acid derivative; Metabolic product
Common use Supports cellular health and metabolic balance
Origin Endogenous substance / Direct metabolite

Samyr is a pharmaceutical product containing the active ingredient Ademetionine, chemically known as S-adenosyl-L-methionine (SAMe). It is officially classified by the World Health Organization's Anatomical Therapeutic Chemical (ATC) system under code A16AA02, grouping it with amino acids and derivatives within the category of products acting on the alimentary tract and metabolism. Ademetionine is an endogenous substance and a crucial direct metabolite, naturally synthesized in the body from the essential amino acid L-methionine and adenosine triphosphate (ATP). This unique origin positions it as a therapeutic compound that replenishes a vital, naturally occurring biological element. The active compound is also sold under other trade names globally, such as Heptral and Transmetil, indicating its widespread pharmacological recognition.


Samyr’s Pharmaceutical Form and Therapeutic Purpose

The formulation of Samyr includes both enteric-coated tablets for oral administration and a lyophilized powder for solution used for intravenous (IV) or intramuscular (IM) injection. The oral form requires the enteric coating because Ademetionine is chemically vulnerable and would otherwise be destroyed by stomach acid, a critical feature differentiating it from standard oral supplements. The fundamental general purpose of providing Ademetionine is rooted in its essential role as the body's primary universal methyl donor in the process of transmethylation, a core biological process. S-adenosyl-L-methionine is involved in a variety of fundamental biological functions, including those that influence cell membrane stability and the synthesis of neurotransmitters. By facilitating these core metabolic reactions, which include the synthesis of the major protective antioxidant Glutathione, Ademetionine is used to support vital cellular regeneration and metabolic balance.

What side effects are possible with Samyr?

Possible Side Effects and Safety Information

The safety profile of Samyr (Ademetionine) is based on clinical trial data and post-marketing surveillance as reviewed by regulatory authorities. The information below details documented adverse reactions, categorized by frequency and the body system affected.


Adverse Reactions by Frequency

Side effects are categorized by how often they occurred in studies:

  • Common (ge 1/100 to <1/10): Headache, Diarrhea, Nausea, Abdominal pain, Anxiety, Insomnia.
  • Uncommon (ge 1/1000 to <1/100): Dizziness, Dry mouth, Vomiting, Hot flush, Agitation, Confusional state, Pruritus, Hypersensitivity, Injection site reactions.

Adverse events are grouped by System-Organ-Class (SOC) and include disorders of the Gastrointestinal system, Nervous system, and Psychiatric disorders.


Serious Adverse Reactions and Safety Constraints

Rare, clinically significant adverse reactions and important safety limitations are officially documented:

  • Serious Reactions: Reports include rare but severe reactions such as anaphylactic or anaphylactoid reactions and laryngeal edema, requiring immediate medical attention. In patients with depression, there are reports of switching to a hypomanic or manic state.
  • Contraindications: Samyr is contraindicated in patients with a known hypersensitivity to the product. It is also contraindicated in individuals with genetic defects affecting the methionine cycle, such as cystathionine beta-synthase deficiency or Lesch-Nyhan syndrome.
  • Population-Specific Warnings: Use is not recommended or contraindicated in patients with bipolar disorder due to the risk of inducing mania. Patients should be advised about potential interference with homocysteine immunoassays, which may result in falsely high readings.

Time-Related Patterns

Some adverse events, such as anxiety, have been reported as transient or worsening initially, with resolution noted after dosage reduction or discontinuation.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for Ademetionine (Samyr) overdose indicates that cases are rare. As the active ingredient is an endogenous metabolite, regulatory documents generally do not list specific severe or life-threatening manifestations typically associated with synthetic drugs.


Required Emergency Actions and Management

Action Domain Official Regulatory Statement
Immediate Action Required The guidance requires that physicians contact their local poison control centers for the latest treatment guidelines.
Antidote Information No specific antidote is known or documented for Ademetionine overdose.
Management Treatment for a suspected overdose consists solely of providing symptomatic and supportive treatment.
Monitoring Patients who have experienced an overdose should be monitored by healthcare professionals.

This structure establishes that emergency medical care focuses on monitoring and supportive measures in all suspected scenarios. The regulatory guidance for when to seek urgent help is triggered by the requirement to contact poison control, ensuring expert guidance for observation and supportive care.

Therapeutic Uses of Samyr

Samyr (Ademetionine) is commonly used across conditions presenting with symptoms related to systemic imbalance, primarily targeting three distinct symptomatic domains.

Supporting Comfort and Stability

The medication is generally applied across domains where additional symptomatic support is needed, including managing intrahepatic cholestasis, certain mild to moderate depressive syndromes, and the chronic pain and stiffness associated with osteoarthritis. Applied in clinical settings that involve heightened systemic burden, Samyr is relevant for easing symptoms linked to organ-specific functional stress, such as pruritus (itching) and chronic fatigue associated with reduced bile flow. The supportive relief provided helps ease the overall symptom burden and helps improve day-to-day comfort during symptomatic phases.

In contexts involving mood and emotional disturbance, the therapy assists with maintaining functional stability and may help patients cope more steadily with symptom fluctuations. For musculoskeletal discomfort, it is relevant for managing symptoms related to physical discomfort, assisting with maintaining functional stability in the affected joints.


Quick Fact: Relief for Cholestatic Pruritus
Samyr is commonly used when symptoms interfere with daily comfort, providing supportive relief for the pruritus (itching) and fatigue linked to impaired bile flow.

Eligibility and Restrictions for Use

Official Eligibility Profile for Samyr (Ademetionine)

Category Regulatory Statement
Absolute Contraindications Must not be used in patients with a known hypersensitivity to Ademetionine or its excipients. It is also contraindicated in patients with genetic defects affecting the S-adenosylmethionine (SAMe) cycle, such as homocystinuria.
Strong Restrictions Use is not recommended in patients with bipolar disorder or those prone to manic episodes, as the medicine may induce or worsen mania.
Age Limitations Safety and efficacy have not been established for use in the pediatric population (children and adolescents). Use in the elderly requires caution, and treatment should generally begin at the lower end of the dose range.
Pregnancy & Lactation Use in pregnancy (especially the first trimester) and during lactation is only advised if clearly necessary and the potential benefit outweighs the potential risk, as documented in regulatory guidelines.
Conditional Use Patients with Vitamin B12 and/or Folate deficiency should have these deficiencies corrected prior to or concurrent with Samyr treatment. Caution is advised in patients with renal impairment.

What should I know about interactions with other medicines?

Pharmacodynamic Serotonergic Interactions

Official regulatory documents classify the co-administration of Ademetionine with certain medicinal products that increase serotonin levels as an interaction requiring specific constraints. The combination with Monoamine Oxidase Inhibitors (MAOIs), such as Tranylcypromine, is designated as a contraindicated combination due to the risk of significant additive serotonergic effects.

Caution is formally recommended for use with other agents known to raise serotonin levels. This pharmacodynamic constraint applies to medication classes including Selective Serotonin Reuptake Inhibitors (SSRIs) and Tricyclic Antidepressants (TCAs), such as Clomipramine. Similarly, the same caution is officially noted for co-use with over-the-counter or herbal supplements containing Tryptophan. These restrictions are based on the documented potential for developing Serotonin Syndrome.

Metabolic and Nutrient Interaction

A documented interaction exists related to essential cofactors required for the metabolic pathway of Ademetionine. A deficiency in Vitamin B12 or Folate may decrease ademetionine levels in the body. Official guidance states that in at-risk patient populations, management of these specific deficiencies is recommended prior to or concurrently with the administration of Ademetionine to support appropriate drug levels.

Mechanism of Action

The Pleiotropic Mechanism of Ademetionine (SAMe)

The mechanism of Ademetionine is purely metabolic; it functions as an essential endogenous co-substrate, not by receptor binding, regulating three central biochemical pathways vital for cellular homeostasis.

Core Mechanistic Role: Universal Methyl Donor

Ademetionine acts as the sole provider of the activated methyl group ( CH3), essential for the Transmethylation pathway, which drives the synthesis and turnover of phospholipids and certain neurotransmitters. This mechanism supports the stability and functional integrity of cell membranes and modulates neuronal signaling, contributing to a functional effect on CNS pathways.

Enhanced Cellular Capacity via Transsulfuration

This pathway links Ademetionine's action to cellular defense systems by acting as an allosteric activator of the enzyme Cystathionine beta-synthase. This accelerates the generation of Cysteine, the rate-limiting precursor for the powerful antioxidant Glutathione (GSH). Increased GSH enhances the cell's capacity for detoxification and oxidative stress management.

Metabolic Action on Tissue Structure and Repair

Ademetionine fuels the Aminopropylation pathway, which generates polyamines required for cell growth and renewal. This influence supports the synthesis of key structural macromolecules like proteoglycans, aiding the body's natural capacity to maintain the structural integrity and repair capacity of connective tissues.

Dosage and Administration Information

How to Use Samyr: Official Administration Guidelines

This section outlines the standardized usage instructions for Samyr (S-adenosylmethionine) based on established product characteristics.


Administration and Dosage Forms

Samyr is provided in two main pharmaceutical formats for administration:

  • Enteric-coated tablets for Oral administration.
  • Powder for solution for injection for Parenteral administration (Intravenous [IV] or Intramuscular [IM]).

Official Dosing and Regimen Structure

Administration Route Typical Daily Dosage Range Administration Frequency
Oral (Tablets) 200 mg to 1600 mg Once or Twice Daily
Parenteral (IV/IM) 200 mg to 800 mg Once or Twice Daily

Treatment often begins with a parenteral phase (injection), typically followed by a transition to the oral tablets for a maintenance phase. The duration and specific dose are determined by the healthcare provider based on the clinical indication.


Preparation and Administration Procedures

  1. Oral Tablets: The tablets are enteric-coated and must be swallowed whole without crushing, breaking, or chewing. They should be taken on an empty stomach (e.g., 30 minutes before or 2 hours after a meal) to optimize the intended absorption profile.
  2. Injections: The powder for injection requires reconstitution with the specified solvent immediately prior to use. Intravenous administration must be performed slowly and is typically managed by a healthcare professional.

These instructions define the standardized procedure and required conditions for correctly administering the medicine.

Recent Clinical Evidence

Samyr: Recent Clinical Evidence

The available research on Samyr (Ademetionine) has examined study findings across three main contexts: intrahepatic cholestasis, certain types of depressive syndromes, and outcomes related to physical discomfort from osteoarthritis. The findings described below reflect patterns observed in groups of patients during clinical trials, not individual predictions or certainties.

Evidence for Use in Intrahepatic Cholestasis

Research designs for intrahepatic cholestasis include short-term randomized controlled trials (RCTs) and systematic reviews that examine combined trial data. Studies monitored changes in key biochemical markers, such as Total Bilirubin, Alkaline Phosphatase, AST, and gammaGT. Research also monitored changes measured during the study period for outcomes related to systemic or functional discomfort, such as the severity of pruritus (itching) and chronic fatigue associated with reduced bile flow. Findings were mixed, as consistency in the observed shifts of all measured biochemical markers varied across the research. Long-term outcomes are not well characterized; follow-up durations were limited.

Evidence for Use in Mild to Moderate Depressive Syndromes

Research for this use primarily included randomized controlled trials (RCTs) and systematic reviews. The studies monitored shifts in total scores on validated depression rating scales (such as the HAM-D). This research examined how symptoms evolved in the observed populations when Ademetionine was studied as a single therapy or as an adjunct to conventional antidepressant medication. Certainty remains low due to the variability in study designs and patient populations, and findings were mixed regarding the consistency of reported changes.

Evidence Gaps and Uncertainties

The evidence highlights what is known—and what is still uncertain. Across all indications, sample sizes were modest in many of the studies, and follow-up durations were limited, with most data covering only short-term symptom changes. Comparative evidence is lacking for certain active standard treatments, and data for certain groups, such as children or older adults, remain insufficient.

Key Studies & References

  1. WHO ATC Index: A16AA02 (Ademetionine) - Amino acids and derivatives

Frequently Asked Questions (FAQ)

Common questions about Samyr (FAQ)


Q: Do you have to take Samyr every day?

Official product information indicates that Samyr is typically part of a daily treatment regimen. The specific length of time this regimen lasts is determined by the healthcare provider based on the treated condition. The specific regimen is established by the prescribing healthcare provider.


Q: Is there a maximum time frame for how long someone can use Samyr?

The duration of treatment is conditional and is decided by the prescribing healthcare provider. In some official contexts, such as for certain chronic liver conditions, the active ingredient's use has been documented in research protocols for up to two years. Treatment duration is subject to ongoing clinical review by the healthcare provider.


Q: What is the difference between Samyr and other SAMe products sold as supplements?

Samyr is a pharmaceutical product, meaning it is manufactured and regulated according to the strict standards of the governing health authorities in its region and is often available by prescription. The active ingredient, Ademetionine, is also sold as a dietary supplement. Differences are noted in the regulatory oversight, as the pharmaceutical form is manufactured according to government-mandated quality standards.


Q: Is Samyr typically taken in the morning or evening?

Official administration guidelines recommend taking Samyr tablets on an empty stomach to ensure optimal absorption, such as 30 minutes before or two hours after a meal. While the required frequency is typically once or twice daily, the specific time (morning or evening) is determined by the healthcare provider based on the individual's schedule and clinical needs.


Q: Do people report feeling energized or tired when starting Samyr?

The safety profile lists some common side effects that can affect perceived energy levels, including anxiety, insomnia (difficulty sleeping), and dizziness. Conversely, studies examining the product's use in certain liver conditions have monitored its capacity to reduce chronic fatigue associated with the disease. Any changes in perceived energy levels are part of the information reviewed during consultation.


Q: What should be done if someone experiences minor side effects from Samyr?

Most minor side effects, such as mild gastrointestinal discomfort, are often temporary and may lessen as the body adjusts to the medicine. Official guidance notes that managing mild side effects like diarrhea may involve drinking fluids or taking the medication with food, provided this is consistent with official administration guidelines. If side effects persist or are concerning, consultation with the healthcare provider is recommended.


Q: Is Samyr a type of antidepressant?

Pharmacologically, Samyr is officially classified as a metabolic product and an amino acid derivative, sometimes categorized as a hepatoprotector (supporting liver function). However, due to its action on neurotransmitter synthesis, it is noted in research to have been examined for its antidepressant activity and has been studied as a treatment option for certain depressive syndromes.


Q: Does Samyr need to be kept refrigerated?

General storage instructions for the active ingredient advise keeping the product in a cool and dry place away from moisture and direct sunlight to maintain its stability. Specific product labeling should always be consulted for the precise temperature limits (e.g., 25 C or 30 C). Regulatory documents typically do not mandate refrigeration unless explicitly stated on the packaging.


Q: What is Samyr actually used for, besides what the doctor said?

According to official authorized indications, the active ingredient in Samyr has been used to address certain liver diseases, specifically intrahepatic cholestasis. It has also been indicated and studied for use in managing certain depressive syndromes and physical discomfort associated with osteoarthritis.


Q: Do you need a prescription to buy Samyr?

In many regions, the pharmaceutical preparation of Samyr is available strictly by prescription and must be used under the supervision of a licensed healthcare professional. This is due to its classification as a medicinal product subject to regulatory oversight. In some other markets, the active ingredient is sold as a non-prescription supplement.


Q: How quickly should someone start to feel a change after taking Samyr?

The therapeutic effects of the medicine are typically achieved gradually over time, rather than immediately. Clinical information suggests that for depressive syndromes, the effect may begin in the first week, while noticeable improvements for all conditions may take a few weeks to become significant. The onset of change depends on the specific condition being addressed.


Q: Is Samyr used for treating nerve health problems?

The active ingredient acts as an essential co-substrate that supports the synthesis of neurotransmitters and the functional integrity of cell membranes, which are important for nerve signaling. Regulatory science indicates that by supporting these core biological processes, the active compound contributes to maintaining neurological balance.


Q: What happens if a dose of Samyr is missed?

Official instructions advise that if a dose of Samyr is missed, it should be taken as soon as the patient recalls it. However, if it is already close to the time for the next scheduled dose, the recommendation is to skip the missed dose entirely and simply resume the regular dosage schedule. Official instructions caution against taking two doses at the same time to compensate for a missed one.


Q: Is Samyr known to interact with common pain relievers?

Regulatory information indicates that potential interactions have been noted with certain common pain relievers. These may include drugs such as tramadol and acetaminophen (paracetamol). Regulatory documents state that caution is generally advised and that patients should keep their healthcare provider informed of all medicines being used.


Q: Are there different strengths of Samyr tablets available?

Yes, the active ingredient is commercially supplied in various oral dosage forms, typically as enteric-coated tablets. The most common strengths available in the market are 200 mg and 400 mg per tablet. These different strengths are available to fulfill the prescribed daily regimen.


Q: Are there warnings about driving or operating machinery while using Samyr?

Official warnings advise patients to exercise caution when engaging in activities requiring full alertness. If side effects such as dizziness or sleepiness occur after taking the medicine, official warnings state that the medicine is associated with a need to avoid driving or operating heavy machinery.


Q: How does Samyr affect the body's natural levels of SAMe?

The pharmaceutical preparation is intended to replenish the body's levels of the endogenous molecule S-adenosyl-L-methionine (SAMe). Regulatory science states that by supplementing this essential compound, the drug helps to fill any existing deficit and stimulate its natural production, thereby contributing to the balance of metabolic reactions within the cell.


Q: Is Samyr associated with any risk to cardiovascular health?

Safety information indicates that the use of high doses can potentially cause an increase in homocysteine levels. Homocysteine is a naturally occurring amino acid, and elevated levels are recognized as a risk factor for certain cardiovascular diseases. This factor is part of the clinical considerations for determining the appropriate treatment dosage.

How should Samyr be stored and disposed of?

How to Store and Dispose of Samyr?

Official regulatory documents define specific requirements for the storage, handling, and disposal of Samyr (S-Adenosylmethionine) to maintain its quality and safety.

Requirement Storage and Handling Profile
Temperature & Packaging Store the product below the specific temperature limit defined on the label (e.g., 30 C or 25 C). Keep the container tightly closed and in its original packaging to protect the product from moisture and light, which ensures stability until the expiration date.
Safety & Handling Keep the medicine strictly out of the reach and sight of children. Store the product away from heat, hot surfaces, sparks, and open flames.
Disposal Disposal of all unused medicine and the container must be conducted in strict accordance with local, regional, and national regulations. To prevent environmental release, unused or expired medication should not be flushed down a toilet or sink, but should be offered to a licensed professional waste disposal service.

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

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