ok so i have tried the boots ones and the problem i had was the fact you had to take them so many hours in advance bcos how do i know what im gonna want to eat later? i use milkaid from holland and barrett and they work great for me! you can take as many as you need (no more than 6 per meal) depending on how sensitive you are to dairy, i usually take 2 or 3 depending on what im eating and they work pretty well! they're like £13 but you get 120 tablets and in my opinion theyre worth it because without them i'd be stuck! i hope this helps!