Lin, i took them for about 3 months before i took a 2nd SA. Must continue to take as sperm needs to take about 2-3 months to mature. We did IVF. Nonetheless, you still need active sperms to make good fertilized embryos.
In general, 1) no handphone in side pockets, 2) wear boxers only at home, 3) try not to wear jeans when going out, 4) no sauna, steam bath or hot jaccuzzi, 5) drinks lots of fluid, 6) high intake of food with anti-oxidant, 7) those supplements, 8) get rid of unused sperms every 3-4 days (according to Dr Loh, older sperm is much less active and quality not so good. no need to keep and have a blast cos production is on a daily basis).