Both Nolva and Clomid are SERMs, selective estrogen receptor modulator. These two work by binding to the estrogen receptors and flooding them in a sense, making it difficult (not impossible) for estrogen to bind to the receptors and thus prevent the onset of estrogen related side effects. They will NOT solve existing Gyno issues. They will prevent (at proper dosing) Gyno.
If you decide to run estro protection while on a blast (for me)'or cycle which most of the vets here recommend, you can run either a SERM or an AI. Letro will be the most powerful AI you can use(check the FDA website for specifics), it will inhibit 98+% of estrogen using a dose as low as .25mg and maybe even lower as different people react differently. It will kill your sex drive! I have seen many posts where guys doing this say they feel like sh#%.
There is no need to take Nolva or Clomid if you are taking Letro.
When you get the gyno under control you need to taper down the letro just like you ramped it up. With your estrogen being completely inhibited there is a definite estrogen rebound as your body tries to re-stabilize the testosterone:estrogen balance. You prevent this rebound effect by supplementing further with another AI or SERM. So, when you are coming to the end of your cycle you will more than likely be using Nolva in your PCT so just make sure that you begin taking Nolva the last day you are going to take your letro and then continue on as you would with regular PCT.
This is the best I can remember, but it is on point.