from that link
9. What is post cycle therapy?
Post cycle therapy is a tried and true method of helping to solidify your gains by raising natural testosterone levels and lowering estrogen levels once your cycle is over. When you add external hormones to your body, your own natural production becomes suppressed. Your body attempts to compensate your endocrine system by stabilizing the other hormones, which results in an increase in estrogen. Once you quit supplying your body with external hormones, your natural testosterone will be low and estrogen will be high. Therefore, anti-estrogens are taken to halt the manufacture of estrogen in the body. This will result in higher testosterone levels, hence making it easier to keep your gains. Post cycle therapy should begin the next day after the prohormones have stopped being taken. Common post cycle therapy drugs are listed below with dosages:
6OXO
6oxo is an aromatize inhibitor sold by Ergopharm. It is the best over the counter anti-estrogen available for post cycle use.
Week 1 – 600mg daily in two divided doses, morning and night
Week 2-3 – 400mg daily
Week 4 – 300mg daily
Formasin/Formastat/Aromazap
Note: 4 hydroxy androstenedione acts as a weak androgen and can cause further suppression of natural testosterone, but can be used post cycle.
Dosages should be 250mg a day for the first two weeks, followed by anywhere from 50-250mg a day for the next two.
Clomid
Clomid is a prescription fertility drug, but is highly available and highly effective at blocking estrogen and increasing LH output.
Day 1 – 300mg
Day 2-11 100mg
Day 11-21 50mg
OR
150mg daily for 2 weeks
100mg daily for 2 weeks
Nolvadex
Nolvadex is also a prescription, which is highly available and blocks estrogen at the receptor.
Week 1-2 – 40mg daily
Week 2-4 – 20mg daily
There are other prescription anti-estrogens available, but these two will be fine unless side effects arise, so we won’t discuss the other options in this FAQ.
Other common post cycle favorites including high doses of flax oil, ZMA, tribulus and an ECA stack coupled with reduced training volume and increased calories (500 or so above maintenance). But, it is very important to use an anti-estrogen for post cycle. I would never recommend not using one unless the cycle length is 2 weeks or less.