Testosterone Isocaproate

Testosterone Isocaproate (Test Iso) is a medium-acting ester of testosterone.

It is almost never sold as a standalone product. It exists primarily as a component of testosterone blends like Sustanon 250 or Omnadren. Its pharmacological purpose is to bridge the gap between the fast-acting esters (Propionate/Phenylpropionate) and the very long-acting esters (Decanoate) to prevent a dip in hormone levels mid-week.

Quick Specs

Mechanism of Action

Standard testosterone functions. The Isocaproate ester allows for a release profile that sits comfortably between Enanthate and Decanoate.

Pharmacokinetics & Dosing

Half-Life: ~9 Days

• Role in Blends: In Sustanon, the Propionate peaks immediately and drops by day 2-3. The Phenylpropionate carries the load until day 4-5. The Isocaproate is designed to keep levels elevated from day 5-10, smoothing the transition to the heavy Decanoate ester.
• Standalone: If it were used solo (rare), it would be dosed similarly to Testosterone Cypionate or Enanthate (once or twice weekly).

Primary Effects

Same as all testosterone variants:

1. Muscle Growth
2. Recovery
3. Libido Support

Side Effects & Harm Reduction

1. Standard Test Side Effects

Aromatization (Gyno, Water Retention) and Androgenic effects (Acne, Hair Loss).

Tracking Test Isocaproate

Using the Anabolic Tracker app:

• Note: You will likely not be tracking this individually unless you have a custom brew. Usually, you will track Sustanon 250.
• Plotter: The Cycle Plotter in the app automatically accounts for the Isocaproate content when you select "Sustanon 250" as your compound.