5aOHP
5aOHP (chemical name: 17beta-{1-Ketoethyl}-androstane-3-one, 17a-ol) is an anabolic progestin that converts to Stanolone, which is better known as dihydrotestosterone or DHT for short. This causes 5aOHP to act like Winstrol because it helps achieve a lean look and adds mass without aggression. However, there is one major difference between winstrol and 5aOHP – the latter one will not cause any hair loss that is commonly associated with the use of winstrol.
1,4-OHP
1,4-OHP (chemical name: 17beta-{1-Ketoethyl}-androsta-1, 4-diene-3-one, 17a-ol) is a precursor to boldenone; just like equipoise, this particular compliant prohorome will increase appetite and enhance recovery. Due to the appetite increase, 1,4-OHP is often used in a bulking stack, where it will help build “wet” mass without adding significant water quickly when compared to something like 4-Andro.
6-Keto-Progesterone
This compliant prohormone is very unique because it works on a completely new and different pathway. It is not an anabolic, progestin, or an estrogen, but 6-Keto still yields muscle growth and mass gains without the harsh side effects. Due to this, 6-Keto is the perfect compliant prohormone to stack with virtually any other prohormone. 
Arimistane
Arimistane (Androsta-3,5-diene-7,17-dione) is a metabolite of 7-Keto DHEA, which does not convert into testosterone or estrogen. In fact, just like the drug Anastrazole, it is actually a suicide aromatase inhibitor (AI), so it will permanently bind to the aromatase enzyme and prevent any estrogen rebound.
BEAST also packs a powerful, all natural, mass matrix composed of some of the best ingredients nature has to offer, like Bulbine Natalenesis…
Bulbine Natalensis encourages increases in muscular development & strength, and improves sex drive & mood. It specifically increases the signalling of Gonadotropin-Releasing Hormone (GnRH) to stimulate the release of Luteinizing Hormone (LH) which directly increases the natural production of testosterone.