1 year ago


Omnadren® 250 (in its original formulation), was an oilbased  injectable testosterone blend that contained four  different testosterone esters: testosterone propionate (30 mg); testosterone phenylpropionate (60 mg); testosterone  isocaproate (60 mg); and testosterone caproate (100 mg). Being a four-component testosterone blend, this preparation  was most commonly compared to Sustanon® 250. While it  did contain testosterone propionate, phenylpropionate, and  isocaproate in the same strengths as Sustanon®, the last ester  is different. It was a slightly shorter-acting drug, making  Omnadren® more analogous to Testoviron® (the caproate  ester is one carbon shorter than enanthate) than Sustanon®  250. Please note that there were even older versions of  Omnadren® listing isohexanoate and hexanoate as the final  two ingredients, which are simply different words for  isocaproate and caproate.


Omnadren® 250 was developed in Poland by Polfa during  the years of Soviet control. Its formulation (original) is very  similar to that of Sustanon® 250, barring the substitution of  one of the component esters. This was likely done to avoid  patent issues with the international pharmaceutical giant  Organon, which exclusively controlled the global supply of  Sustanon® 250. In clinical medicine, Omnadren® 250 was  used most commonly to treat adult men suffering from low  androgen levels, usually noticing symptoms of impotence or  hormonal disturbance of spermatogenesis. This drug was  also used on occasion to treat adolescents with delayed  puberty, and women with advanced breast or endometrial  cancer. The manufacture of Omnadren® 250 under the Polfa label  was discontinued in 1994. That year, the newly privatized  Polfa firm was renamed Jelfa, mainly to distinguish itself  from other firms that use a Polfa prefix as part of their names. Jelfa continued to produce Omnadren® 250 for the domestic  market, which remained available without interruption in the  same familiar 5-pack of ampules (albeit with a new company  label and logo) for years after.

Structural Characteristics:

Omnadren® 250 contains a mixture of four testosterone  compounds, which where modified with the addition of  carboxylic acid esters (propionic, propionic phenyl ester,  isocaproic, and caproic acids) at the 17-beta hydroxyl group. Esterified forms of testosterone are less polar than free  testosterone, and are absorbed more slowly from the area of  injection. Once in the bloodstream, the ester is removed to  yield free (active) testosterone. Esterified forms of  testosterone are designed to prolong the window of  therapeutic effect following administration, allowing for a  less frequent injection schedule compared to injections of  free (unesterified) steroid. Omnadren® 250 is designed to  provide a rapid peak in testosterone levels (24-48 hours  after injection), and maintain physiological concentrations  for approximately 14 days.

Side Effects (Estrogenic):

Testosterone is readily aromatized in the body to estradiol  (estrogen). The aromatase (estrogen synthetase) enzyme is  responsible for this metabolism of testosterone. Elevated  estrogen levels can cause side effects such as increased  water retention, body fat gain, and gynecomastia. Testosterone is considered a moderately estrogenic steroid. An anti-estrogen such as clomiphene citrate or tamoxifen  citrate may be necessary to prevent estrogenic side effects. One may alternately use an aromatase inhibitor like  Arimidex® (anastrozole), which more efficiently controls  estrogen by preventing its synthesis. Aromatase inhibitors  can be quite expensive in comparison to anti-estrogens,  however, and may also have negative effects on blood lipids. Estrogenic side effects will occur in a dose-dependant  manner, with higher doses (above normal therapeutic levels)  of testosterone more likely to require the concurrent use of an  anti-estrogen or aromatase inhibitor. Since water retention  and loss of muscle definition are common with higher doses  of testosterone, this drug is usually considered a poor choice  for dieting or cutting phases of training. Its moderate  estrogenicity makes it more ideal for bulking phases, where  the added water retention will support raw strength and  muscle size, and help foster a stronger anabolic environment.

Side Effects (Androgenic):

Testosterone is the primary male androgen, responsible for  maintaining secondary male sexual characteristics. Elevated  levels of testosterone are likely to produce androgenic side  effects including oily skin, acne, and body/facial hair growth. Men with a genetic predisposition for hair loss (androgenetic  alopecia) may notice accelerated male pattern balding. Those concerned about hair loss may find a more  comfortable option in nandrolone decanoate, which is a  comparably less androgenic steroid. Women are warned of  the potential virilizing effects of anabolic/androgenic  steroids, especially with a strong androgen such as  testosterone. These may include deepening of the voice,  menstrual irregularities, changes in skin texture, facial hair  growth, and clitoral enlargement. In androgen-responsive target tissues such as the skin, scalp,  and prostate, the high relative androgenicity of testosterone is  dependant on its reduction to dihydrotestosterone (DHT). The 5-alpha reductase enzyme is responsible for this  metabolism of testosterone. The concurrent use of a 5-alpha  reductase inhibitor such as finasteride or dutasteride will  interfere with site-specific potentiation of testosterone  action, lowering the tendency of testosterone drugs to  produce androgenic side effects. It is important to remember  that anabolic and androgenic effects are both mediated via  the cytosolic androgen receptor. Complete separation of  testosterone’s anabolic and androgenic properties is not  possible, even with total 5-alpha reductase inhibition.

Side Effects (Hepatotoxicity):

Testosterone does not have hepatotoxic effects; liver toxicity  is unlikely. One study examined the potential for  hepatotoxicity with high doses of testosterone by  administering 400 mg of the hormone per day (2, mg per  week) to a group of male subjects. The steroid was taken  orally so that higher peak concentrations would be reached in  hepatic tissues compared to intramuscular injections. The  hormone was given daily for 20 days, and produced no  significant changes in liver enzyme values including serum  albumin, bilirubin, alanine-amino-transferase, and alkaline  phosphatases.


•    17beta-hydroxy-androst-4-en-3-one
•    Molecular Weight (of Base): 288.429
•    Molecular Weight (esters)
•    Propionate: 362.5082
•    Phenylpropionate: 438.6058
•    Isocaproate: 404.5886
•    Caproate:116.16
•    Formula (of Base): C19 H28 O2
•    Formula (esters)
•    Propionate:C3 H6 O2
•    Phenylpropionate:C9 H10 O2
•    Isocaproate:C6 H12 O2
•    Caproate:C16 H12 O2
•    Melting Point: 154-155C
•    Manufacturer: Jelfa
•    Effective dose: 250-1,000mgs/week
•    Active Life: 10 days
•    Detection Time: 3 months
•    Anabolic/Androgenic Ratio: 100:100