Randomization in this study will be performed at the individual level using block randomization with a 1:1 allocation ratio. To maintain balance between the intervention and control groups, variable block sizes of 4 and 6 will be used. The random allocation sequence will be generated before participant enrollment using computer-generated random numbers by an independent person who is not involved in participant recruitment, assessment, or follow-up.
After confirming each participant’s eligibility and obtaining informed consent, a unique study code will be assigned according to the order of enrollment. Group allocation will then be performed according to the pre-generated random sequence.
For allocation concealment, group assignments will be placed in sequentially numbered, opaque, light-impermeable, sealed envelopes. The envelopes will be opened in numerical order only after the participant has been formally enrolled and baseline information has been recorded. The person responsible for generating the random sequence and preparing the allocation codes will have no role in participant recruitment, outcome assessment, or data analysis.
As the study is double-blind, the mountain barberry extract and placebo will be made similar in appearance, capsule form, packaging, and administration schedule, and will be identified only by study codes. Therefore, both participants and outcome assessors will remain unaware of the assigned intervention.
This study is designed as a randomized double-blind clinical trial. After obtaining written informed consent and confirming eligibility, participants will be randomly allocated into either the intervention group or the control group using a random number table.
Participants in the intervention group will receive the investigational drug, while those in the control group will receive the standard routine treatment according to the approved therapeutic protocol. To ensure proper blinding, the investigational drug and the routine medication will be matched in appearance, color, size, packaging, and administration schedule, and will be provided in coded containers.