When I take Rx1, my face feels very prickly and warm. Am I having an allergic reaction?

What you're likely experiencing is a completely benign side effect that should only last 30-60 minutes max. Most people only experience this for 5 minutes or so. What's causing this is the high dose of a supplemental ingredient called Beta Alanine. Within Rx1 X-Cite, there is 3,200 mg of Beta Alanine per serving. This has been a very powerful supplement in research and it's showing that it has huge effects in our ability to train with more intensity within a 60 second window of time. 

If the benign side effects of Beta Alanine are unpleasant for you, consider cutting back the dosage by taking 1/2 scoop servings. Do this for a couple weeks and your body will start to acclimate to the ingredient, which can allow you to tolerate a full 3,200 mg dose over time. Eventually, you will work up to a 3/4 scoop serving and finally 1 level scoop.