Testosterone Undecanoate 250 mg

Testosterone Undecanoate 250 mg is Hilma Biocare's ultra-long-acting testosterone injectable, supplied as a 10 ml vial at 250 mg/ml. The undecanoate ester produces the longest release window of any common testosterone preparation, with injections spaced weeks or months apart.

What Testosterone Undecanoate Is

Testosterone undecanoate is testosterone esterified with undecanoic acid, an eleven-carbon chain that makes the molecule extremely lipophilic. After intramuscular injection it forms a viscous depot that releases hormone very slowly, producing sustained levels for weeks. The 250 mg/ml strength gives 2500 mg per 10 ml vial. In some markets the same ester is formulated in castor oil at a higher concentration for even longer intervals.

The History of Test Undecanoate

Testosterone undecanoate was developed in the 1970s and first marketed as an oral capsule under the Andriol name before long-acting injectable versions appeared. The injectable formulation was introduced in the 2000s for testosterone replacement, with dosing intervals measured in weeks rather than days. It represents the logical endpoint of ester engineering: the longer the chain, the fewer administrations are needed to maintain stable levels.

How It Works

The undecanoate ester is cleaved very slowly by esterases, so free testosterone enters circulation gradually and remains elevated for an extended period. Peak levels arrive days after injection and decline over several weeks. As with all testosterone esters, the released hormone binds the androgen receptor and is aromatised to oestradiol and reduced to dihydrotestosterone. The ultra-long ester minimises fluctuations but also means a long washout once administration stops.

What the Research Shows

• Injectable testosterone undecanoate has been studied in long-interval replacement therapy.
• Trials report stable trough levels with injection intervals of several weeks.
• Its pharmacokinetics are among the slowest of any testosterone ester.
• The long washout is a recognised consideration in research design.

Research Context

Undecanoate's ultra-long action has been studied for replacement therapy with injections spaced several weeks apart. Trials show stable trough levels and good tolerability, although the long washout means that adverse effects can persist after discontinuation. The ester is also available as an oral capsule in some markets, but the injectable form provides far more predictable absorption. Research has examined its effects on bone density, lipid profile and prostate parameters over multi-year periods.

Strength, Pack and Authentication

Each vial contains 250 mg of testosterone undecanoate per millilitre, for 2500 mg in 10 ml. It is filled under controlled conditions, sealed with a colour-coded flip-off cap and packed in a printed carton stating the compound, strength and volume. A scratch-off security code inside the box can be verified against Hilma Biocare's records.

Buying Testosterone Undecanoate Online

Ultra-long testosterone esters are a growing search category. If you are researching testosterone undecanoate, comparing long-interval testosterone products or looking to buy test undecanoate online from a trusted Hilma Biocare supplier, this page gives you the full specification, pack size, price and stock status. Browse more Hilma Biocare injectables at NotNatty.