1,4-andro (1,4-androstadienedione) and 1,4-androdiol (1,4-androstadienediol) are both prohormones to the steroid boldenone. 1,4-andro is well known as the most orally active prohormone, with a recovery rate as high as 50%. This is because its chemical structure renders it resistant to first pass metabolism in the liver. However, unlike many other steroidal compounds, the chance of liver toxicity from oral administration is very low.

Boldenone (1,4-androstadiene-3-one,17b-ol) is an injectable veterinary steroid most commonly found as Equipoise (used for horses). It is structurally related to testosterone and methyl-testosterone, and a small amount (10-20%) may metabolize into testosterone. It is very popular among bodybuilders and other athletes because of its unique characteristics. It is highly anabolic, while having only low-moderate androgenic effects and low estrogenic effects. This is because it is a poor substrate for 5-alpha reductase and has low aromatization to estrogen. Boldenone is commonly stacked with other steroids, and it has the reputation of leading to smaller, more consistent, and easier to keep gains as opposed to rapid muscle gains which are difficult to maintain off cycle. Other reputed effects of boldenone include increased pumps and muscle hardness and increased appetite.

A low dose of 1,4-andro falls in the range of 300-600 mg daily, with a medium dose being in the range of 600-1000 mg. It is good for both cutting or bulking, and can be stacked with most compounds depending on the situation. Cycle length is usually on the longer side, around 4-12 weeks, because it usually takes around 3 weeks for most users to notice an effect. This is because boldenone has a long half-life, so the effects build up over time. The difference between the dione and diol versions is that the dione version converts to estrogen (at about half the rate that testosterone does), while the diol version does not.