The purpose of this research study is to determine the safety and efficacy of 10XB-101 vs. vehicle (placebo) for adults with excessive submental fat (SMF).

Inclusion Criteria:

• Subject is a male or non-pregnant female 18 to 65 years old.
• Subject has provided written informed consent.
• Subject has qualifying Submental Fat evaluation score.
• Subject has had a stable body weight for the past 6 months prior to starting study.
• Subject is willing to undergo test article injections as directed, comply with study instructions, and commit to all follow-up visits for the duration of the study.

Exclusion Criteria:

• Subject is pregnant, lactating, or is planning to become pregnant during the study.
• Subject has loose skin in the submental area, diffuse SMF, or prominent platysmal bands at rest that may interfere with evaluation of localized fat, in the opinion of the investigator.
• Subject has had any prior treatment for SMF (e.g., deoxycholic acid, cryotherapy, liposuction, surgery).
• Subject has any medical condition that affects clotting and/or platelet function
• Subject has a history of allergy or sensitivity to polidocanol or any of the other ingredients in the test articles.