They are different products. BULK-UP is 4dhea and aDHEA and bDHEA. These ph's convert to test and dht. These would be the base of a solid cycle or a great stand alone. Libido will be solid and energy levels will be good.
Alphamass is a great 1DHEA based product. Usually used with a 4dhea based product due to some users experiencing libido lowering and lethargy. I for one never experienced this with 1dhea. 1dhea converts to 1test.
Both are great products and include an effective delivery system. You can feel good about purchasing either. Personally I would go with both stacked but like I said either alone will not disappoint. I personally have found recovering from all three of these PH 4dhea, 1 dhea, adhea and bdhea to be rather easy as compared to methylated DS.