Test-U250
Specifications:
-
Packaging:
1 vial / 10 ml -
Concentration:
250mg/ml -
Active Substance:
Testosterone Undecanoate -
Active Half-life:
21-34 days -
Group:
Injectable Line -
Subgroup:
Testosterones -
Recommended Dosage:
1000-2000mg per month -
Oil-based:
Grapeseed oil -
Retains water:
Yes -
Aromatization:
Yes
Product Description:
What it is and How it Works
Testosterone Undecanoate (Test U) is one of the longest-acting Testosterone esters available. Once injected, it releases Testosterone very slowly, maintaining elevated hormone levels for several weeks. Because of its extended half-life, it is often prescribed in medical settings for TRT, where injections may only be required every 6 to 12 weeks depending on the protocol.
Like other forms of Testosterone, it binds to androgen receptors, stimulating protein synthesis, nitrogen retention, and red blood cell production. This results in improved strength, muscle growth, recovery, and endurance. It also converts into estradiol and DHT, both essential for libido, mood regulation, and overall vitality.
Possible side effects include water retention, acne, oily skin, accelerated hair loss in genetically predisposed individuals, gynecomastia from estrogen conversion, and cardiovascular strain through altered cholesterol and hematocrit levels.
How is it used?
Due to its very long half-life, Testosterone Undecanoate requires far less frequent injections than other esters such as Enanthate or Cypionate. In medical TRT, injections are often scheduled once every several weeks.
For bodybuilding purposes, however, the long release makes it less practical. Because the ester takes longer to build up and clear, it is not ideal for cycles where fast adjustments or precise control of blood levels are desired. Effects typically take 5 to 6 weeks to fully stabilize.
Dose
This product is dosed at 250mg/ml × 10ml. In TRT, doctors usually prescribe 250 to 1000mg every 6 to 12 weeks depending on patient response. For performance enhancement, doses of 1000 to 2000 per month may be used, though this ester is far less common in bodybuilding compared to Enanthate, Cypionate, or Propionate.
Advice From BTW
- Be patient
Test U builds up slowly and takes several weeks to reach steady-state levels.
- Not cycle-friendly
Because of its long half-life, it is difficult to control quickly, making it less suited for bodybuilding cycles where fast adjustments are needed.
- Good for TRT
Its extended duration makes it convenient for long-term medical therapy with fewer injections.
- Bloodwork timing
If using it for TRT, schedule labs mid-way between injections to get an accurate picture of hormone levels.
- Consider alternatives
For most athletes, shorter esters like Test E or Test C offer more flexibility and control.
FAQs
- How often do I need to inject Testosterone Undecanoate?
In medical TRT, it is often injected every 6 to 12 weeks. Bodybuilders typically inject more frequently if using it for performance purposes.
- Is Test U better than Test E or C?
Not necessarily. Its main advantage is convenience in TRT, not performance enhancement. Test E and C are more practical for bodybuilding.
- How long does it take to feel the effects?
It usually takes 5 to 6 weeks for blood levels to stabilize and for effects to be fully noticeable.
- Why do bodybuilders rarely use Test U?
Because of its extremely long half-life, it is difficult to control estrogen, adjust dosage, or transition in and out of cycles efficiently.
- Is Test U safe for TRT?
Yes, it is often prescribed for TRT. Its long action allows fewer injections and more stable hormone levels over time.
Protection code:

How it works:
BTW Labs prioritizes consumer well-being and continually develops various protective measures for its products, ensuring both patient safety and trust in the verification of our products.
Why Choose Us?
How it works:
We take pride in providing products that meet the highest standards of quality and consistency. Every batch is third-party tested to ensure accurate dosing and purity, so you know exactly what you are putting into your body. Our packaging is designed for both safety and discretion, and our customer support team is always available to provide guidance. Whether you are a beginner or an advanced athlete, choosing us means choosing reliability, trust, and a partner who values your performance and well-being.