Raynaud's Phenomenon (RP) is a condition where small blood vessels in the skin have spasms, causing reduced blood flow. People with RP may feel pain, sensitivity to cold, or notice color changes in their hands. In severe cases, it can lead to tissue damage. This study explores if Botulinum toxin (BT), a medicine often used to relax muscles, can help those with RP that doesn't respond to usual treatments. The study will test two doses of BT (10 and 20 units) compared to a saltwater solution (placebo).

Participants will be evaluated at regular times for changes in finger temperature, oxygenation, and tissue condition. If you are 18 or older and have moderate to severe RP that hasn't improved with regular treatments, you might qualify for this study.

• This study is held at Emory University and involves 36 participants.
• There is no external recruitment; participants are referred from specific divisions.
• The goal is to find the right dosage and injection method for treating RP.