Pigmentation recurrence rates: ① melasma: 50–70% recurrence within 1 year without maintenance, 20–30% with proper care, ② sun spots: 30–40% (depends on sun exposure), ③ post-inflammatory: low recurrence after fully healed. Prevention: ① strict daily SPF 50+ year-round, ② avoid hormonal triggers (pregnancy, contraceptives if possible), ③ continued herbal medicine support, ④ maintenance laser sessions every 3–6 months, ⑤ avoid skin trauma/aggressive treatments.