i took L-Arginine, L-Histidine and zinc before and upped my loads by a significant amount. i was also a lot hornier. you can find out about the functions of these aminos in wikipedia. there's a lot of hoohah about what actually works, but i think the nitric oxide production and stimulation of endocrine system helps. taking chinese yang tonics also helps - jin gui shen qi wan for example. but if your body doesn't need it, you're just going to burn yourself out. i agree with fri2219 and my recommendation would be to eat lots of leafy greens and live a healthy lifestyle.
one more thing: i read the book "the multiorgasmic male" by mantak chia, and practiced his daoist jing saving technique. it allowed me to have multiple orgasms, and after about the 10th "dry" orgasm, i'd let rip and basically drop a large omlette all over my partner. it was pretty intense but takes a lot of work to get it right.