Several treatments for obesity have received regulatory approval, but health insurers and other payers typically refuse to support access to them. Thus, patients are left to bear significant out-of-pocket costs for obesity pharmacotherapy. This study aimed to assess preferences and willingness to pay (WTP) for obesity medications among people seeking weight loss in the United States and United Kingdom. An online survey was developed based on literature review, clinician interviews, and profiles of available therapies. Participants indicated their preference for hypothetical treatments which varied by seven attributes: percentage of weight loss, long-term health risk reduction, time to noticeable weight loss, delivery mode, side effects, lifestyle modification, and cost; 502 obese participants completed the survey (mean BMI 37.12 kg/m(2) (±4.63); 73.5% female; 47.7 (±12.9) years of age). The participants deemed weight loss of >21 kg (United Kingdom) and >28 kg (United State) as "acceptable". All treatment attributes were important (P < 0.001) except "time to noticeable weight loss." The survey found that percentage weight loss was the most important factor for patients and a reduction in long-term health risk was relatively less important. Patients were willing to pay £6.51/$10.49 per month per percentage point of weight loss that a pharmacotherapy could provide. Participants also highly valued therapies that did not require substantial lifestyle modifications and were willing to pay £17.78/$30.77 more per month for a one-pill-per-day treatment vs. a weekly injectable. Participants placed a high value on weight loss and avoiding changes to their lifestyle, and less value on reducing long-term risks to health.