Weirdly, semen kind of healthful. It contains protein (for shiny hair and strong nails!), zinc, vitamin C, and sugar. But “the amounts of proteins and vitamins that you’d ingest from giving oral sex are negligible,” says ob-gyn Amanda Meulenberg, MD. If you’re looking to blowies for daily nutrients, you’re better off taking a multi-vitamin. And when a guy drops that line again, know that you don’t have to, um, swallow it.