I think what Totentanz said about supression and cholesterol is right but it also depends on the type of a chemical being used.
If the supplement company 'science' behind methylated Epitiostanol is corrrect, you have a legal compound that acts as an estrogen blocker and would be a good choice for pulsing since it would initially increase LH, therefore endogenous test production on the off days during a pulse cycle.
It also supposedly binds relatively strongly to androgen receptors, so that it would be perfect as a cutting agent or a body recomposition drug.
I tried pulsing for two weeks during a cut.
In my limited experience, I lost 3.0 lbs of fat and gained 0.8 lbs of muscle (I was cutting) the first week and did not experience any 'emotional roller-coaster'. The only side effect was increased libido.
Also, I'm 6 days post my last 40mg workout dosage and libido is normal (no shutdown?...possible).
If this is all true, this would be an amazing 'supplement' to use in an HST fashion.
My theory is that two week periods will provide you with slightly increased anabolism and help with the fat burning, but should not affect HPTA and cholesterol levels to a high degree.
Remeber, this is an un-proven theory. There are a lot of user experiences you can check out online, but it would be nice to see a double-blind research study looking at all of this. Nothing I have found as of yet, except this:
2a 3a-Epithio-5-androstan-17ß-ol in Treatment of Gynecomastia
It's also important to note that many users would not suggest oral only cycles, since most of the gains are lost post-cycle. It seems that some orals will bind to glucocorticoid receptors preventing cortisol binding. This, I think, is one of the reasons for joint pain many feel. Post oral cycle also, is a big problem when catabolism (glucocorticoid receptor increase maybe?...) takes over and you lose most of what you gained. And, I'm not talking using aromatizable orals like D-bol, because those gains seem to be mainly water weight.
Therefore, in my opinion, it is best to have only a slight nudge in the anabolic direction (a two week, pulsing, methylated epitiostanol, HST fashion, bulking) to prevent crashes and muscle loss, post-cycle. This is opposed to long, heavy, very anabolic cycles, possibly followed by long and heavy catabolic body response.
Seems logical, for every action there is a reaction. The bigger the action, bigger reaction will follow.
This might be also good for cholesterol (I'll be checking mine). I can keep you posted if you want.
Or.....you can go with a 5-8 week full blown cycle, but everybody recommends test as a base for this, and of course a proper PCT including Arimidex, Nolva, HCG. I just don't like messing with that many drugs. And, Nolva is carcinogenic...
Cheers