Product Overview
It is a four-ester testosterone blend in a 350 mg per ml oil, supplied in a 10 ml vial. Propionate, phenylpropionate, isocaproate and decanoate carry the same hormone at four different speeds, so one injection starts releasing within days, the middle arms hold the level between shots, and decanoate covers the tail. This page describes the composition, the release curve, the dose bands, the stack arrangements inside the British Dragon range, the recovery window and the storage rules.
Sustabol 350 is one androgen, not four different drugs. Each ester is testosterone with a different acid chain attached, and that chain decides how fast esterase enzymes in the blood cut the hormone free. British Dragon declares propionate, phenylpropionate, isocaproate and decanoate on the pack, in the order in which the release begins.
The 350 mg per ml strength is what separates this vial from the older 250 mg per ml clinical formula built on the same four-ester idea: the 10 ml vial carries 3500 mg of labelled testosterone, so a weekly dose needs less oil and fewer draws.
One caveat belongs here. The sources checked for this card confirm which esters the vial contains but record no per-millilitre split for this product, and the clinical ancestor is diluted differently, so any exact breakdown of the 350 mg that you read elsewhere is unverified. What is documented is the shape of the curve.
The oil depot in the muscle breaks down slowly and the esters pass into the blood, where they are hydrolysed into free testosterone. Propionate has an elimination half-life of about 0.8 days after an intramuscular injection and decanoate about 5.6 days in blood. No half-life figure is recorded for phenylpropionate or isocaproate, whose contribution is read from the curve rather than from numbers.
The clinical four-ester product peaks near 70 nmol per litre about 24 to 48 hours after a 250 mg injection, then drifts back towards the lower end of the normal male range by around the third week. Splitting a weekly total into two or three shots lifts the trough without lifting the peak much, which is the reason a blend is chosen over one long ester.
The hormone still aromatises into estradiol, so water, blood pressure and breast tissue follow blood work rather than the ester list, and an effective dose still switches off the body's own output. With decanoate at the end of the formula, that suppression cannot be ended quickly.
Dosage Protocol
No approved dose exists for this product, and no source checked here states a protocol written for the 350 mg per ml vial. The rows below come from the general testosterone sheet held with this card and from the vendor range published for multi-ester products of this class.
| Entry level | 250-350 mg a week, one millilitre or less, split into two injections over 10-12 weeks |
| Middle of the range | 400-600 mg a week every three to four days, with estradiol checked at week three or four |
| Higher end | 600-750 mg a week over 12-16 weeks, only with hematocrit, lipids and estradiol tracked |
| Female | No confirmed female protocol for this formula; virilisation makes it unsuitable |
| Administration | Deep intramuscular injection every three to four days, rotating sites and warming the oil first |
Two things separate this vial from a single ester. Enanthate or cypionate alone needs the same twice-weekly schedule but starts more slowly, while propionate alone acts within a day and asks for injections every other day. The concentration is the second difference: less carrier oil for the same weekly dose, and a longer tail than a short-ester cycle, so the recovery window is planned from the first week rather than improvised at the end.
Suggested Protocols
Because the blend is pure testosterone, every partner in a cycle is there for a reason: more size, a drier look, or control of estrogen. The three arrangements below open cards from the same brand, so a cycle can be assembled without leaving the British Dragon section.
Estrogen control is the same on all three. Water and pressure are managed with Anastrozole at a dose set by blood work, and a mass run that adds fluid quickly is where that matters most.
What to Expect
- Days one to three. Propionate is already releasing, so blood levels move before the long arm contributes anything.
- Weeks one and two. Phenylpropionate and isocaproate take the middle of the curve and the level flattens if shots stay three to four days apart.
- Weeks three to six. Strength, fullness and libido move on the usual testosterone timeline, while water and pressure follow estradiol.
- Estrogen early. With a short arm present, estradiol can run high in the first fortnight, so a test at week three or four beats waiting for the slow arm.
- The long exit. Decanoate governs the tail, so the last shot fixes the earliest possible start of recovery.
- Injection site. At 350 mg per ml the oil is concentrated, so smaller volumes given more often usually feel better than one large shot.
- The limit. Plain testosterone behind four esters: it changes onset and injection count, not the role of diet, protein and training.
Side Effects and Management
The esters control timing only. The profile below is the one that applies to any effective dose of testosterone.
Blood pressure, hematocrit and lipids are the three readings that decide whether a run continues, and all three come from one blood draw.
Post-Cycle Therapy
Suppression follows the dose, not the ester, and a blend does not soften it. The mix only changes the waiting time: the restart is worth starting once the depot has largely emptied, and the decanoate end of the formula sets that date.
Write the last injection date down, because every test after it is read against that date, and do not open a second cycle before the markers return to their starting point.
Storage and Handling
The oil is what needs care. Keep the vial upright at room temperature, roughly 15 to 25 degrees Celsius, in its box or another dark place away from sun and radiators. Refrigeration is not needed for an oil-based product and only makes the solution thicker and slower to draw.
If a vial has been stored cold and shows crystals or a haze, warm it in the hands and roll it until the oil clears; do not shake it. Wipe the stopper with an alcohol swab, let it dry, use a fresh needle for every draw, and never share a vial. Discard it if the solution stays cloudy, changes colour or holds particles, and dispose of needles in a sharps container.
