Chemical structure: 2 alpha-methyl-17 beta-hydroxy-5 alpha-androstan-3-one
Molecular weight of base and ester: 360.5356
Anabolic/Androgenic Ratio: 62/25
Active Life: 2-3 days Masteron (Drostanolone Propionate) is perhaps one of the more ‘exotic’ androgenic / anabolic steroids (AAS) that may be used by an athlete. Originally it was developed and used as an anti-estrogen (under the name Masteril) for the treatment of breast cancer. It was largely used in combination with the SERM (Selective Estrogen Receptor Modulator) Tamoxifen (aka Nolvadex) for the treatment of breast cancer, and did give a significant decrease in estrogen levels in women undergoing such treatment. It is not much used these days for such purposes, for varying reasons, however for many athletes including competitive bodybuilders in particular; Masteron remains a rather unsung favourite of AS medicines.
The fact that Masteron was being used as an anti-estrogen goes to suggest quite a lot about some properties Masteron possesses. Masteron is a derivative of DHT (dihydrotestosterone) and does not convert to estrogen through means of aromatisation. It is thought that the anti-estrogenic properties of Masteron may be in part to do with either an inhibition in some way of the aromatase enzyme or an interaction with estrogen itself in a way which blocks receptor binding of the estrogen. Either way, this would put Masteron as a useful tool for the AS user who uses compounds that convert to estrogen (which most AS users do, considering testosterone is the main basis of most cycles). By inhibiting the aromatase enzyme, Masteron would be in effect blocking the conversion of free testosterone to estrogen by the aromatisation pathway. This would not only serve to marginally increase the amounts of active free testosterone in circulation (thus giving a greater effect of the testosterone over a Masteron-free system), but it would also negate the side-effects that result from high levels of estrogen due to aromatisation. Such side effects include the development of gynecomastia and water retention/bloating. Conversely, if Masteron actually blocks the binding of estrogen to the estrogen receptor (ER) in some way, although aromatisation of testosterone may occur, its effects would be limited due to the inability of the estrogen to bind to the ER. Thus through this mechanism, the effects of excess estrogen production through aromatisation would also be limited by use of Masteron.
Although Masteron contains such anti-estrogenic properties, it also (being a DHT derivative) has anabolic and androgenic properties. Although in theory and on paper it may be seen to be not a very strong androgen, in fact Masteron does give higher androgenic effects than one may expect. The use of Masteron, as it is an AAS, will shut down natural testosterone production and so despite having anti-estrogenic effects again, one must not think that Masteron could be used as an option in post cycle therapy as it will inhibit recovery.
There are two forms of Masteron that are generally available for use – Drostanolone Propionate andDrostanolone Enanthate. The propionate version is usually dosed at 50-150mg/ml and is the fast acting version of Masteron, needing to be injected every other day. The enanthate version of Masteron is dosed normally at around 200mg/ml and needs only to be injected twice per week as the ester attached to the drostanolone is longer thus giving a slower release of hormone.
Due to the effects of Masteron on estrogen related side effects, Masteron is a very useful tool (especially in competitive bodybuilding) when cutting. As higher levels of estrogen result in water retention, Masteron inhibits water retention, and many users claim that their muscles feel very full and tight on Masteron, with it giving them amazing ‘muscle pumps’ in the gym. Use of Masteron (in combination with other appropriate meds) at low body fat levels results in the user seeing fine detail of the muscles being accentuated, such as striations and the fine details of the muscle. Masteron helps draw out the water from between the skin and the muscle giving this very cut look (at low body fat levels). Not many other AS medicines can give such effects on muscle detail as those seen with Masteron.
Despite these effects of Masteron, it is a rather weak AS in itself. One would hardly benefit at all from use of Masteron on its own, and furthermore use of Masteron alone may result in loss of libido due to shutdown of the body’s natural testosterone production. For these reasons, it is always recommended to stack Masteron with other steroids.
It is said by many that using Masteron is a waste when the user has a body fat percentage higher than 10-12%. I can understand the reasoning, and the user must understand that at higher body fat levels the detail to the muscle will not be seen in such a way as described; however I do not see it as a waste due to its anti-estrogenic properties. Such properties may allow one to not use other ancillaries on cycle that would have other undesirable side effects, and in addition Masteron may work in a synergistic fashion with other AS medicines to amplify their effects (for example with testosterone as described above). Masteron would however not be recommended for beginner use as it is not needed at this starting out level.
350-500mg per week (propionate version, injected every other day)
400-600mg per week (enanthate version, injected twice per week)
An example of an excellent cutting cycle for an advanced user would be: (6-10 weeks)
150mg Testosterone propionate every other day
50mg Trenbolone acetate every day (or 100mg every other day)
150mg Masteron (propionate) every other day
50mg Winstrol every day, last 4 weeks of cycle only
Of course with such an intermediate/advanced cycle, the user could also incorporate other medicines such as Clenbuterol, Ephedrine, T3, growth hormone, IGF, etc.
A more novice cutting cycle may consist of: (6-8 weeks)
100mg Testosterone propionate every other day
100mg Masteron (propionate) every other day
Possible Side Effects
As discussed, Masteron possesses anti-estrogenic properties which results in the elimination of many of the unwanted side effects that AS users may experience, such as gynecomastia, water retention and dangerous increases in blood pressure. Although Masteron is a weak steroid and on paper it has low androgenic properties, it has already been mentioned that in practice the androgenic properties appear to be slightly higher than in theory, and secondly Masteron is a DHT derivative. For more detailed information on DHT and the results of excess DHT in circulation see the ‘Possible Side Effects’ section of the articleTestosterone as an Anabolic Steroid.
Briefly however, the side effects that may occur with use of Masteron include hair loss (if prone to male pattern baldness), aggression and acne. If a user does experience acne with other androgens such as testosterone, then it is a real possibility that they may experience it with the use of Masteron. I know of people who experience only a few spots with the use of testosterone however when using Masteron they experience many more spots. On the other hand, there are users who seem to experience less spots on Masteron than they do on Trenbolone.
As with all AAS, it is impossible for anyone to say how an individual will definitely react in terms of side effects, etc with any medicine, as individuals will always differ in their responses to medicines, with differing severities as well. But the user must be aware that the potential is there, and thus take this into consideration when planning a cycle. There are medicines available to combat side effects, such as finasteride for baldness and accutane for acne, however these medicines also have their limitations and must be researched well before use.
Having said this, Masteron when initially produced pharmacologically, was seen by the FDA as a relatively safe medicine, even at high dosages. Dosages in excess of 150mg per day (that’s over 1000mg per week) were considered as safe limits by the FDA (bear in mind most other AAS used by athletes are used in levels that exceed FDA safe limits). This is good news to the user, however do not misinterpret this information as a reason to use excessive doses of Masteron as in reality anything above 600mg per week is not going to give any more benefit than 500-600mg per week would give, thus excessive use would be a waste of money and injections.
How Masteron Compares to Other Steroids
Many have called Masteron a “weak” steroid, but this definitely is not the case. What often has been weak has been the doses! Doses of this drug have historically been low because of rarity, price, and low concentration of the preparations (100 mg/mL.) However, both availability and price have improved markedly in recent years.
When included as part of a steroid stack, Masteron’s contribution per milligram is at least as great as that of testosterone, boldenone (Equipoise), nandrolone (Deca), or methenolone (Primobolan.) But of course, if only 100 or 200 mg is added per week, there will be no large change seen from such a small addition.
Masteron can be used as the sole injectable: in this case, I prefer to see dosing of 500-700 mg/week. A Masteron/Dianabol stack is more effective however, as is a Masteron/Anadrolstack. Testosterone also combines well with Masteron.
Another use of Masteron which has become more common lately is combination with trenbolone. Unlike combination with Dianabol or Anadrol, there is only an additive effect, not a synergistic effect. However, including Masteron allows a lower trenbolone dosage while achieving very similar or equal physique benefit with less potential for trenbolone-specific side effects of night-sweats, increased tendency to aggression, and/or insomnia.
Masteron also is useful in combination with testosterone for self-prescribed hormone-replacement therapy (HRT.) For example, 100 mg/week each of Masteron and testosterone can be superior for physique benefits to 200 mg/week testosterone alone, while being milder in side effects due to lower resulting levels of estradiol (estrogen) and DHT.