What is Test Mix (high dose)?
Test Mix is a highly concentrated oil solution with the same four testosterone esters as classic Sustanon, only in a much larger amount per ml. A vial holds 10 ml. Composition per ml:
- 400 mg/ml: 60mg testosterone propionate, 120mg testosterone phenylpropionate, 120mg testosterone isocaproate, 100mg testosterone decanoate.
- 500 mg/ml: 60mg testosterone propionate, 120mg testosterone phenylpropionate, 120mg testosterone isocaproate, 200mg testosterone decanoate.
The two versions differ only in the decanoate share, so the 500 version lasts longer.
This information is for research and educational purposes only. No medical advice.
Comparison
Four esters in one oil
Which testosterone esters each oil contains, as stated in the TPD lexicon. Tap a card to open its entry.
Simplified: short esters act fast and briefly, long ones slowly and for longer. The mix combines both.
How it works
All four esters are cleaved in the body and release testosterone. It binds the androgen receptor and raises protein synthesis, nitrogen retention and red blood cell production. Part of it is converted to estradiol and to DHT.
Propionate kicks in fast, phenylpropionate and isocaproate follow and decanoate releases the compound for the longest time. The high concentration does not change the effect; it only means less oil per dose.
Where it acts
One receptor, several organs
Tap a point or a card. Grey = effect seen in trials.
- Hypothalamus and pituitary
LH suppressed as long as testosterone was raised, one to two days with propionate5
Observed in trials - Testes
Sperm production suppressed: no sperm in 65 percent after 6 months, recovery within months after stopping6
Observed in trials - Blood
Haemoglobin and haematocrit rose with the testosterone dose, more in older men3
Observed in trials - Liver and blood lipids
HDL cholesterol fell as testosterone levels rose2
Observed in trials - Heart
Pumping function lower in long-term users (52 vs 63 percent), more coronary plaque4
Observed in trials - Fat tissue
Fat mass fell as testosterone levels rose2
Observed in trials - Skin
Acne in 28 of 100 users, breast tissue growth in 197
Observed in trials
Targets in the ChEMBL database10
Compound CHEMBL386630: one recorded mechanism, agonist with direct binding to the human receptor.
- Gene
- AR
- UniProt
- P10275
- ChEMBL
- CHEMBL1871
- Action
- Agonist, direct binding
Use and dosing
Dosing
Dosing, titration and syringe
Loading the dosing information …
- Getting started and stepping up, drawn as a staircase
- Units on the U-100 syringe for every step
- How long one vial lasts
Injection
The oil is ready to use. Intramuscular injection into the glute, thigh or shoulder is recommended; disinfect and rotate sites.
- Thicker needle to draw, thinner needle to inject.
- At 400 to 500 mg/ml the oil needs more solubilizers, which can burn or ache more at the site.
- Subcutaneous is not recommended: short esters and high concentration irritate subcutaneous fat more.
What the research shows
There are no studies on this high-dose blend itself. Forsdahl and colleagues (2015) examined the four esters in the Sustanon composition in a doping control study: all esters were detectable in blood after one injection and the detection window depended on the ester.
Bhasin's dose-response trial (2001) shows that muscle mass and strength rise with the dose while HDL falls. Coviello and colleagues (2008) found a dose-dependent rise in hemoglobin and hematocrit. Baggish and colleagues (2017) saw weaker heart pumping function and more coronary plaque in long-term anabolic steroid users.
Study results
What the trials measured
Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.
Fat-free mass after 20 weeks2
Gain in kg in the three higher of five dose levels of testosterone enanthate, the body's own production was switched off with medication
The two lowest levels are not shown here. Strength, haemoglobin and IGF-1 rose with the testosterone level while fat mass and HDL cholesterol fell. Trial with testosterone alone.
How long levels stay raised after one injection5
Days (d) above the lower limit of the normal range, healthy men and men with hormone deficiency
LH stayed suppressed for as long as the level was raised. The enanthate dose was much higher than the two propionate doses, so the comparison shows ester and amount together.
Pumping function of the heart4
Left ventricular ejection fraction in percent, experienced strength athletes aged 34 to 54
Cross-sectional study, users with at least 2 years of total use. Coronary plaque had a median of 3 vs 0, the longer the total use, the more plaque.
Research status
Where the research stands
There is no study on the highly concentrated mix. Shown is the only registered trial with the same four esters at a lower concentration. As of 26 Oct 2026. 9
- Preclinical How anabolic steroids act in animals and cells (review)
- Phase 1 no registered trial
- Phase 2 no registered trial
- Phase 3 no registered trial
- Approval all four esters as medicines, this concentration without a study of its own
Show all 1 phase 4 trial on a timelineHide timeline
NCT01454011 · 140 participants, started Sept 2008, primary endpoint reached Feb 2011. Tests several agents.
Registry entry ↗ · Results not yet in PubMed
Bar: start to primary endpoint (planned for running trials). Green = completed, blue = progress until 26 Oct 2026.
Side effects
The blend carries the risk profile of every testosterone product. Because high weekly doses fit into little volume, the temptation to overdose is greater.
- Estrogen: water retention, rising blood pressure, gyno risk.
- Hematocrit: rises with the dose, keep an eye on the blood count.
- Heart and vessels: long-term high doses are linked to weaker heart function and more vascular plaque.
- HPTA suppression: your own testosterone production is suppressed.
- Androgenic: acne, hair loss if predisposed.
- Injection site: burning and pain more often than with lower-concentration oils.
Tolerability
Frequency in the HAARLEM study
Out of 100 users, how many had the event. One cohort without a comparison group, participants chose compounds and amounts themselves.
| Event | All 100 users |
|---|---|
| At least one side effect7 | 100% |
| Lower libido after the cycle7 | 58% |
| Fluid retention during the cycle7 | 56% |
| Agitation during the cycle7 | 36% |
| Acne7 | 28% |
| Breast tissue growth (gynecomastia)7 | 19% |
Four participants had a serious event: heart failure, pancreatitis, suicidal thoughts and a flare of ulcerative colitis. One year after the start the observed effects were back at baseline. In this cohort the amount played no visible role in the type and severity of side effects.7
Storage
Keep the oil at room temperature, in the dark and closed. Do not put it in the fridge, as highly concentrated oils crystallize particularly easily in the cold. Visible crystals dissolve when the vial is warmed and swirled until the solution is clear again.
