Testosterone Phenylpropionate

Testosterone Phenylpropionate (TPP) is an esterified form of the natural male hormone, testosterone. It is a synthetic anabolic-androgenic steroid (AAS).

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1. Detailed Explanation / Different Names

• Chemical Structure: TPP is the C17$\beta$ phenylpropionate ester of testosterone.

• Purpose: The phenylpropionate ester is attached to the testosterone molecule to modify its release rate from the site of injection. This creates a "depot" effect, allowing for a sustained but non-linear release of testosterone into the bloodstream over time, compared to un-esterified testosterone.

• Different Names/Trade Names:

  • Testosterone phenpropionate

  • Testosterone hydrocinnamate

  • TPP

  • Trade Names: Testolent (as a standalone product, though never widely used), and as a component in mixed-ester preparations like Sustanon 250 and Omnadren 250.

• Mechanism of Action: Like all testosterone forms, TPP works by binding to the Androgen Receptor (AR), modulating the transcription of androgen-responsive genes, leading to its anabolic and androgenic effects. It is also converted into other active hormones, namely estradiol (via the aromatase enzyme) and dihydrotestosterone (DHT) (via the 5$\alpha$-reductase enzyme).

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2. Side Effects and Benefits

As an anabolic-androgenic steroid, TPP shares the benefits and side effects of testosterone and its derivatives.

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3. Pros and Cons

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4. Dosage and Frequency (Medical/Clinical Use)

Testosterone Phenylpropionate is not typically used alone in modern medicine but as a component of mixed esters like Sustanon 250 or Omnadren 250.

• Standalone TPP (Historical/Rare): Given its intermediate duration, it has been historically listed with a suggested duration of action of approximately 8 days. This would imply a frequency of roughly once every 5-8 days for stable blood levels.

• As part of Sustanon 250 (Common Use): The total dose of the mixture (250 mg) is typically administered every 3 to 4 weeks for hypogonadism treatment. Note: Sustanon contains 60 mg of TPP per 250 mg vial.

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5. Half-Life and Detection Time

• Half-Life (Elimination): Approximately 4-5 days. Clinical data suggests a duration of action of roughly 8 days.

• Detection Time: In blood samples, Testosterone Phenylpropionate has been detected for at least 8 days after a single injection. The detection time for its metabolites in urine would be longer and is highly variable depending on the dose, individual metabolism, and testing methods. Typically, injectable testosterone esters can be detected for several weeks to months (e.g., 3 months for Testosterone Enanthate).

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6. Sterogenic, Progestogenic, Prolactin Effects

• Sterogenic/Estrogenic Effects: TPP is a testosterone ester, and testosterone is readily converted to the potent estrogen, estradiol, by the aromatase enzyme. Therefore, TPP has significant estrogenic activity. This can lead to side effects like gynecomastia and water retention. Anti-estrogens (Aromatase Inhibitors or SERMs) are often required to manage this.

• Progestogenic Effects: Testosterone (and its esters) does not bind to the Progesterone Receptor (PR) and is not considered to have direct progestogenic activity.

• Prolactin Effects: Testosterone and its esters do not directly stimulate prolactin production. However, high levels of estrogen (estradiol), resulting from aromatization, can increase prolactin levels, particularly when estrogen levels are extremely high.

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7. Anabolic Androgenic Ratio

Testosterone, regardless of the ester attached, is the baseline standard for comparing anabolic and androgenic effects.

• Testosterone Phenylpropionate Anabolic:Androgenic Ratio: 100:100

Note: The number represents a comparison to the base standard of testosterone, which is set at 100:100. This indicates TPP has equal anabolic (muscle building) and androgenic (male characteristic) properties.