Chemistry
Superdrol (methasteron) is definitely not a prohormone: it is a very active form of a designer supplement. Superdrol gets its name from the fact that it is a super-saturated, or 2-reduced, form of Anadrol. Anadrol has a =C-OH at the 2nd position, and if this is totally saturated (reduced) with hydrogen, it gives -CH3. Another way to describe it is that it is a 2a-17a-dimethyl of drostanolone (Masteron). Masteron has a single methyl group at the 2nd position. Superdrol is a modification of this structure by adding another methyl group at the 17th position, like M1T or M-Dien. However you may wish to look at it, it is by this simple-looking transformation that Superdrol comes to occupy the sweet spot between the chemical natures of Anadrol and Masteron. Since it is already reduced at the 5th position, it cannot make estrogen. Progesterone is not an issue: perhaps 0.1% can aromatize, in theory. In fact, this compound should not have any major metabolites at all. Maybe a few hydroxylated adrenal metabolites, but only traces. It is basically excreted unchanged as the conjugated glucuronate. The extra electron density at the 2 makes Superdrol 2-3x as anabolic (mg for mg) than Anadrol. To borrow from the language of genetics, Superdrol is a fine example of hybrid vigor: it has only the best attributes of each, and none of the worst. This is a supplement designed to have it all.
Anadrol/oxymetholone 17ß-hydroxy-2-hydroxymethylene-17a-methyl-5a-androstan-3-one
Superdrol/methasteron 2a,17a-Dimethyl-17ß-hydroxy-5a-androstan-3-one
Masteron/drostanolone
2a-methyl-17ß -hydroxy-5a-androstan-3-one
Proviron/mesterolone
1a-methyl-17ß -hydroxy-5a-androstan-3-one
...
Fluid Retention
Masteron and Anadrol are on the opposite ends of the spectrum in regards to fluid retention. In this regard, Superdrol lies close to Masteron, which – being unable either to convert to estrogen or mimic the effects of estrogen – has typically been used for reducing water retention while increasing muscle hardness and density. The rapid gains in mass caused by Anadrol involve not a little water retention: bloating is unavoidable, as with Dianabol/M1,4ADD. With Superdrol, there is no extra water retention. There is not even facial bloating. It forms no estrogen, so the renin-angiotensin-aldosterone (RAAS) system cannot be activated to cause any water retention. M1T has the unfortunate effect of causing water retention in the kidneys, which can be painful, and is definitely unhealthy.
The pumps for which Anadrol is known are caused by an increase in the volume of blood, some of it RBC but much of it water. Blood pressure rises accordingly, and can lead to headaches, other forms of discomfort, or worse. The pumps from Superdrol could well be the result of the volumization of blood without the water gain, as noted above. It is in fact a mild diuretic. This helps contribute to the unmatched vascularity noticed in lean individuals. Because it dries you out, unless you are cutting for a reason, like a contest, you should increase your water intake accordingly. You can expect to drop at least several pounds of water in your first few days of use. From testers who monitored their blood pressure, there was no indication that it rose significantly, nor were there in others symptoms of high BP, for example, face turning beet red, or feeling nauseous after a few light sets. The pumps and increased vascularity from Superdrol are pleasant - “my biceps feel flexed when at rest” in the words of one tester. That is, until the dose is becomes too high, at which point Superdrol shares with Anadrol back pumps, cramps, or aches. These can inhibit workouts. At proper doses, these are fleeting, not unlike those from M1T, but not as severe. However, the tester who challenged the highest dose experienced such discomfort that he literally had to lay on the gym floor in between sets. It seems that Superdrol has a built in mechanism, harmless enough, to prevent its abuse.