EQ profile......it may be a little dated, but here goes;
For something that is generally injected into cows, horses and dogs boldenone is quite a popular and well-liked drug by most bodybuilders because of its unique make-up. It possesses several characteristics that aren't found in any other substance and its use is so varied its much desired year-round. Boldenone is a decent anabolic coupled with both a mild androgenic and a mild estrogenic effect. Sort of like a weak testosterone. In structure it doesn't differ all that much from testosterone, the main anomaly being a double bond in the one position as well as the 4 position. Its nonetheless quite good at promoting gains, but mostly through a combination of androgenic potential and other media than the androgen and estrogen receptors.
The strange thing about its androgenic component is that it is mostly not mediated by a 5-alpha-reduced form, as is the case for most steroids. While it does indeed form a very potent 5AR form (dihydroboldenone, roughly 7 times as anabolic as testosterone1) its shows a very low affinity for the 5-alpha-reducatase enzyme2. This leads to the conclusion that a large part of the anabolic effect boldenone exerts is formed by the hormone itself binding to the androgen receptor. This could also be the reason its had such a successful run as a veterinary drug, because despite differences in the metabolism of species it has always produced extraordinary results.
Like most anabolic steroids it increases muscle mass over time by increasing nitrogen retention and positively influencing protein synthesis or re-synthesis. An action that is not necessarily supported by an androgenic mediator as was shown with nandrolone. What boldenone has that other steroids don't is that it indirectly supplies the necessary means for that protein synthesis because it drastically increases the appetite. Thereby facilitating the high nutritional intake (especially protein wise) needed to book the best results when using anabolic androgenic steroids. Its more of a benefit than you think as a lot of people have theorized that it is this increase that is responsible for the great results booked when using boldenone. This theory may hold its own as there is indeed not much proof of the kind of anabolic activity with boldenone that would be responsible for the elicited effect.
Its estrogenic activities are slight, but present. This has more of a positive than negative influence. The aromatisation of boldenone is too small to cause real problems and in normal doses (300-400 mg/week) problems such as gynocomastia and too much fat retention are unheard of. However small aromatisation is desirable as estrogen too mediates anabolic activity. It can be responsible for better glucose utilization3,4 (repleting lost glycogen stores after exercise) and stimulating increased growth hormone release5. But most notably estrogen is responsible for an upgrading of the androgen receptor6 allowing hormones that act on the androgen receptor to exert a larger anabolic effect. This is why hormones that are strong androgens but also aromatize heavily, like anadrol and testosterone, can put the most mass on your frame. In that aspect boldenone is perhaps the most suitable steroid because of its moderate estrogen levels that allow for the benefits, but not the side-effects of aromatization. And no doubt the perfect balance is partially responsible for stimulation of the appetite.
For athletes of sports other than strength sports or bodybuilding will also note that boldenone is quite likely the most favorable steroid for them to use as it also stimulates the release of erythropoeitin in the kidneys. Erythropoeitin is a hormone known as EPO and heavily abused among endurance athletes because it signals the body to increase the production of red blood cells (erythrocytes). Red blood cells are the carrier of oxygen in the body, meaning that a higher maximal oxygen capacity can be obtained and better performance can be achieved over longer amounts of time before lactic acid is built up, which would in turn result in cramps and a cessation of the activity at that level. In short it improves your stamina. For bodybuilders this characteristic may be useful in promoting increased vascularity.
In that aspect boldenone combined with a non-aromatizing steroid like Winstrol or Primobolan may be perfect to help you get cut and ripped while improving vascularity. The downside to that is that you really need to try hard to suppress the increased appetite. Which is why its probably a better idea to stack a somewhat larger dose of boldenone with a mass building drug like testosterone or anadrol to elicit major gains.
The negative effects of boldenone are quite limited. In the normal doses of 300-400 mg a week estrogenic side-effects are almost never noted except in those who are very succeptible to estrogen. In terms of androgenic side-effects long-term use or very intense use of boldenone can cause slight virilizing effects such as acne and increased body-hair growth. Never really a problem for men, but women considering its use on account of its moderate androgenic qualities should be aware of this.