Like Methandrostenolone (GP Methan), Oxymetholone does not bind well to the androgen receptors, and most of the anabolism it provides is via non-AR-mediated effects. GP Oxy is therefore a Class II steroid and is best stacked with a Class I steroid. GP Oxy appears to give the same benefits as GP Methan 10. Unlike GP Methan Dianabol, however, it seems that Oxymetholone (GP Oxy) is progestagenic. It has been observed to cause nipple soreness or to aggravate gynecomastia even in the presence of high dose antiestrogens, strongly suggesting that the effect is not estrogenic. That effect can be reduced by concurrent use of Stanozolol (GP Stan 10), which is anti-progestagenic. This progestagenic effect of Oxymetholone is only a concern when using aromatizing steroids. With androgens such as Primobolan (GP Prima 100), Oxymetholone stacks very nicely and is a surprisingly friendly drug. In contrast, with testosterone it is a very harsh drug.
GP Oxy Dosage
Compared to what bodybuilders expect of it, GP Oxy is reasonably mild when no aromatizing steroids are present. Is considered GP Oxy’ potency approximately comparable to GP Methan. It is not unusual for a first time user to do quite well on an oxymetholone-only cycle, but more advanced users will want to stack with another steroid. Typical use is 50-150 mg/day, which should be divided into several doses per day.
Because GP Oxy is 17-alkylated, it is stressful to the liver. It is better to limit use to no more than 6 weeks or preferably four weeks before taking a break of at least equal length. Many users feel that it is more effectively used in the beginning parts of the cycle, rather than in the last few weeks.