A total of 120 Chinese male subjects aged 18-50 years who have undergone hair transplantation are planned to be enrolled in this study. Among them, 90 participants with mild-to-moderate scalp seborrheic dermatitis (hereinafter abbreviated as SD) will be stratified and randomly allocated into two groups based on a randomization table with stratification factors including SD severity grading, alopecia classification and age. Subjects in the test product group (hereinafter referred to as the holistic group) will use the test shampoo plus basic shampoo, while those in the basic control group will receive only basic shampoo. The remaining 30 non-SD subjects will constitute the non-SD control group and use basic shampoo alone.

1. Primary Objective To compare pre- and post-treatment changes in clinical, physiological, biological and microecological parameters related to SD manifestations, scalp health and skin barrier repair (including transepidermal water loss, scalp hydration, scalp sebum content, etc.) between the holistic group receiving the investigational shampoo regimen and the basic control group via non-invasive instrumental measurement, clinical assessment, clinical photography and subject self-evaluation. The safety and efficacy of the test product in improving scalp condition and skin barrier function will be evaluated, and its potential underlying mechanisms will be explored.
2. Secondary Objective To investigate the impacts of the test product versus the control shampoo on hair transplant-associated complications (e.g., folliculitis), wound healing, follicular shedding phase, graft survival rate and hair growth parameters among SD patients.
3. Exploratory Objective To collect baseline clinical, physiological, biological and scalp microecological data from non-SD recipients after hair transplantation for reference purposes.

Inclusion Criteria:

1. Healthy Chinese male subjects aged between 18 and 55 years old;
2. Diagnosed with androgenetic alopecia, with alopecia grade from Grade II to Grade VI per Hamilton-Norwood classification;
3. Scheduled to receive hair transplantation; scalp condition is confirmed suitable for trial participation by dermatologist assessment after hair graft surgery;
4. With or without mild-to-moderate scalp seborrheic dermatitis (SD score ranging from 0 to 9);
5. No anti-dandruff shampoo used within the latest 14 days prior to enrollment;
6. No hair dyeing, perming or hair styling cosmetic treatments in the past 30 days;
7. Able to comply with all scheduled study visits;
8. Possess normal communication and comprehension capacity;
9. Agree to regular follow-up visits and complete related questionnaires on time;
10. Fully understand trial procedures, volunteer to join the study and provide written informed consent.

Exclusion Criteria:

1. Suffering from severe scalp seborrheic dermatitis;
2. Received oral or topical antifungal drugs, glucocorticoids or other therapeutic medicines for seborrheic dermatitis within the preceding 30 days;
3. Complicated with other scalp diseases (such as psoriasis), or with obvious infection or unhealed wounds on the target treatment area;
4. Known hypersensitivity to ingredients including selenium disulfide, salicylic acid and related components;
5. History of autoimmune diseases or severe organic diseases involving heart, brain, lung, liver, kidney and other vital organs;
6. Past medical history of psychiatric or psychological disorders;
7. Refuse to sign the written informed consent form;
8. Currently enrolled in another interventional clinical trial;
9. Diagnosed with alopecia areata, pseudopelade, cicatricial alopecia or other scalp and hair disorders;
10. Have taken part in any other clinical trial within the prior 3 months;
11. Judged as inappropriate for trial participation based on investigator's clinical assessment.