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Testo C 250 – Testosterone Cypionate (Royal Pharmaceuticals)

Category: Injectable Testosterone Ester (Research Only)
Brand: Koninklijke Farmaceutische Producten
Concentration: 250 mg/ml testosterone cypionate
Packing: 10 × 1 ml ampoules
Origin: United Kingdom
Price: €49

Research Notice: For laboratory, analytical and collector use only. Not a dietary supplement and not for human or veterinary administration.

🧪 What Is Testosterone Cypionate?

Testosterone cypionate is a long-chain ester of testosterone (testosterone 17β-cyclopentylpropionate). After intramuscular depot formation, the ester is slowly hydrolysed, releasing free testosterone over an extended period.
In a research environment, this compound serves as a reference androgen ester for:

• Androgen receptor (AR) signalling studies
• Pharmacokinetic modelling of long-acting esters
• LC-MS/MS and GC-MS analytical method development
• Anti-doping assay validation and metabolite profiling

This listing describes the chemical and pharmacological properties of testosterone cypionate as an AAS reference material; it is not therapeutic or dosing guidance.

🔬 Mechanism of Action

1. Prodrug Activation

The cypionate ester increases lipophilicity and slows absorption. After injection into muscle tissue, esterases cleave the ester bond, producing biologically active testosterone.

2. Androgen Receptor Signalling

• Free testosterone binds the intracellular androgen receptor
• The AR complex translocates to the nucleus
• Androgen-responsive genes are upregulated
• Protein synthesis and nitrogen retention increase

3. Metabolic Pathways

• 5-α-reduction → dihydrotestosterone (DHT)
• Aromatisation → estradiol (E2)

Both metabolites contribute to androgenic and estrogenic biological activity in research models.

4. Depot Pharmacokinetics

Testosterone cypionate demonstrates a prolonged terminal half-life (~7–8 days in clinical references), yielding sustained serum testosterone elevation for 1–2 weeks after a single injection.

📚 Research Applications

• Androgen receptor gene-expression experiments
• Endocrine and steroid-metabolism modelling
• Chromatographic assay standardisation
• Pharmacokinetic curve comparison between ester types
• Anti-doping research for exogenous testosterone detection

📈 Potential Research-Level Observations

• Increased androgen-receptor signalling vs. baseline conditions
• Sustained testosterone release from depot matrix
• Modification of erythropoiesis markers
• Altered nitrogen balance in controlled systems
• Shifts in androgen/estrogen metabolites under enzymatic pathways

⚠️ Safety Profile & Known Risks (Class Effects of Testosterone Esters)

Endocrine & Reproductive

• Suppression of LH/FSH and endogenous testosterone
• Reduced spermatogenesis and fertility impairment

Cardiovascular & Metabolic

• Reduced HDL-C, possible rise in LDL-C
• Increased hematocrit / polycythaemia
• Potential blood-pressure elevation

Androgenic

• Acne, oily skin, androgenic alopecia
• Virilisation if exposed in females

Hepatic & Other Effects

• Changes in liver enzymes (low hepatotoxicity relative to oral 17-α-alkylated AAS)
• Injection-site irritation or reactions
• Mood shifts or irritability in susceptible models

These are biological class effects of testosterone esters and are provided for research context only.

🛑 Compliance & Legal Status

• Testosterone esters are prescription-only medicines in many jurisdictions.
• Classified under WADA S1 – Anabolic Agents; prohibited at all times.
• Regulated storage, handling and disposal required in laboratory settings.
• Not for human use, performance enhancement, or medical self-administration.

📊 Technical Data Table

For research and analytical use only. Not for human or veterinary administration.