You can’t always get what you want. And, contrary to popular belief, you don’t always get what you need. But at Remede Spa, you can actually get both. The brand new spot opens today in the St. Regis Hotel, and all 9,000 square feet are built to cater to your needs. For starters, their custom facials and massages are genius. Simply choose the amount of time for your treatment (30, 60, or 90 minutes), and the aesthetician helps you come up with treatments appropriate for your needs, whether they’re a fix for fine lines or adult acne. (After all, how the heck are you supposed to know if you should get microdermabrasion? She’s the expert.) Of course, the ol’ standbys are on the menu: hot stone therapy, cellulite treatment, mineral wraps, body bronzing, couples massages, and mani-pedis. Indulge in any of the above while you sip on champagne and nibble truffles. And watch those things you want suddenly become what you need. And vice versa. Remede Spa, St. Regis Hotel, 125 Third Street, between Mission and Howard Streets (415-284-4060).