Tamoxifen(Novladex) will not reverse the gynecomastia, but if you insist on staying on your gear, it can keep it down. One thing you can add is some fat-burning additives, like ephdrine or others. If you've ever seen a woman with big breasts go from a size 12 to a size 4, they lose substantial size on their cup size. The fat from gynecomastia is no different, only it is harder to get rid of.
If you are getting signs, I would re-evaluate your cycle and switch to moving towards Primobolan from CLP, don't buy BD anymore unless you're sure of who you are dealing with and they have old stock(still not sure about BD now). Mix it into your program, slowly integrating more of the Primobolan - methenolone - as you ease off the testosterone cypionate. Although most on this site say no less then 400mg/week, 200-300 will get your natural test going, you can eat less, burn more fat(hopefully some of the gynecomastia unless you've gone too long) and avoid a crash.
Primo can be taken for longer, (200-600max) because it is so easy on the body and does not convert to oestrogen. Also, be aware that if you are sensitive to gynecomastia, 250-300 of testosterone cypionate will still give you the problem and you should probably stay away from anything that can convert to oestrogen in the future. Some people are simply more sensitive. Remember, before passinng the 30 year old mark, you only produce about 70-75mg of natural test, so adding 250 is a huge increase in overall production.
Hope that helps some, it was long and you'll get lots of advice on this. Try searching, you'll get tons of help from some great people here.
If you do stop, don't forget to do a post cycle or it will get way out of control.
40mg nov day one
20 for ten days
10 for ten
and if you want, 5 for ten more. This is farely common for PCT - post cycle therapy - , but there are many other versions.
Best wishes.