Can you legally buy Xanex online w/o a prescription in the US?

NO

Tbo,  You better be careful with what you are trying to do.  If you think you really need some Xanax, see a doctor and take it responsibly.  Xanax is a benzodiazepine and it can be very addictive.  You cannot stop taking Xanax cold turkey, or you may have seizures.  You have to taper off of it very slowly.  Please go and see your doctor and stop trying to find this drug on your own.  I don't want anything bad to happen to you.

Anna Sparky's Mom

There are some online pharmacies that work with doctor's willing to write an Rx without ever seeing or examining you. Please don't fall for that trap and end up with a handful of Xanax, just looking for a cheap thrill. It's a benzodiazapine, very potent, and easy to get a high tolerance to. IF you have a legit need for Xanax, like an anxiety disorder, see a local doctor and get a real diagnosis. It can be a good medication for anxiety, but comes with a lot of side effects and is habit forming after a short time.

IOW, it might get you high for a couple of weeks, but you're gonna have to pay the price when you run out. Is it worth additional nervousness, lack of sleep, and seizures? I don't think so.

No, but you can buy Zanaprin by Lazarus Labs Stop Anxiety, Panic, Stress, New Relaxation & Sleep Aid Bars. Product Features: 

• Combat stress and anxiety
• Feel more calm and under control
• No prescription needed
• Not addictive
• Improve Sleep 

Lazarus Labs has created a new product to fill the gap left by the loss of Benzanax (Benzanex) which was designed by Hi-Tech to relieve stress and anxiety.
Zanaprin is made from natural ingredients and has been formulated to reduce stress and anxiety, improve sleep, and improve mood. These time tested ingredients have been researched heavily and used for many years in countless other products. Zanaprin will assist with relaxation, enhanced mood, memory, and focus, may assist with normalizing blood pressure and the central nervous system, and even be a good support supplement for people who are trying to quick smoking.