Background: Trofinetide is approved for the treatment of Rett syndrome (RTT) in patients aged ≥2 years. Here, we present the benefits and tolerability of trofinetide in the treatment of RTT with the 12-month follow-up of LOTUS. Methods: Caregivers of patients who are prescribed trofinetide under routine clinical care are eligible to participate. Assessments include the Behavioral Improvement Questionnaire (BIQ), the Quality-of-Life Inventory-Disability (QI-Disability) Questionnaire, and the Gastrointestinal Health Questionnaire. Due to ongoing enrollment, data are reported to 9 months since the initiation of trofinetide. Results: In total, 192 patients were included. The median dose reported at week 1 was 45.0% of the target weight-banded label dose; by week 9 onwards, the median dose was at least 80.0% of the target weight-banded label dose. Behavioral improvements reported with the BIQ were nonverbal communication (49–62%), alertness (43–62%), and social interaction/connectedness (32–52%). The QI-Disability Questionnaire median total scores indicated overall improvement in quality of life (QoL) with trofinetide. Caregivers reported that patients were most likely to void normal stools over the follow-up; most reports of diarrhea were contained inside the patient’s diaper. Conclusions: Caregivers of patients with RTT in LOTUS reported behavioral improvements of RTT symptoms and improvement in patients’ QoL.