有讀者問，平時勤力做 面膜 Mask 護理，對保養皮膚有沒有功效? 常聽到有些面膜，可以塗抹過夜，比一般的面膜 Mask 更有療效，更保濕，是不是越長時間，效果越好?

首先是面膜 ABC，什麼是面膜 Mask? 從美容醫學角度，是否有療效⋯ 為什要做 Mask ?
大家是專家吧! 簡單來說面膜的療效有以下:
補濕，令皮膚感覺嫩滑
幫助修復受損皮膚
控油，殺菌，控制暗瘡
祛死皮，清潔
刺激皮層膠厚蛋白製造，收緊皮膚，抗衰老
美白，淡斑 ⋯ 等功效

以面膜的形式，含較高濃度的有效成份 (比一般日霜晚霜所含的)，塗抹一段短時間，約十五至三十分鐘，然後被抹去及清潔。這樣的護理，可增強有效成份的功效和吸收，減低有效成對皮膚的刺激性。高濃度，短時間的皮膚接觸，比低濃度的長時間接觸，更為溫和，更有效 (接近八成功效)。
皮膚長時間在濕潤的狀態，也會減低皮膚的抵抗力，引起刺激過敏反應。

既然是含較高濃度和有刺激性的有效成份，必須給予皮膚充份的休息時間。最少四十八小時，或更長的復元時間，否則可能對皮膚有傷害，形成慢性發炎，不但影響皮膚質素，也可能惡化原有的狀況。

一般在皮膚表面產生效用的成份，面膜是有效的輸送媒體，如控油，祛死皮，控菌，修復皮膚表面 (Barrier Repair)。

至於能否深層吸收面膜中的成份，膠原蛋白，透明質酸 (高份子及低份子) … 我是有所保留。皮膚的功效，是免疫系統的第一防線，抵擋外來化學物質，病毒，細菌 ⋯ 膠原蛋白是蛋白質，病毒細菌的蛋白也是蛋白質，所以 ⋯

不要以為，做面膜的時間越長或次數越多，越有效 ⋯
必須要用得其法，建議要懂得選擇有質素，有效處理問題的面膜產品，一星期一次，每次不多於三十分鐘。

Facial masks are effective in applying therapeutic ingredients, especially those that may be unstable or have a significant risk of irritation. Masks are particularly attractive for people with sensitive skin because it has been documented with prescription retinoids that such a product applied for up to one hour (then rinsed off) still achieves about 80% of the activity of overnight application with less irritation.

Masks are available in a variety of formulations, such as gels, creams clays or alignate masks that can be peeled off the skin.

Oily and acne-prone skin types will benefit from drying masks prepared with clay or kaolin to absorb excessive sebum; magnesium, sulfur, zinc pyrithione, selenium sulfide or benzoyl peroxide to treat acne; and tretinoin for treatment of extrinsic aging, acne or psoriasis.

Problem skin that is also sensitive may find a gel mask made with white willow bark extract, azelaic or salicylic acid to be antimicrobial as well as soothing to the skin.

Some masks are formulated with “healing” enzymes such as papain and bromelain or mushroom extract to help reduce scaling after chemical peel or microdermabrasion treatment.

Patients/clients with dry and/or sensitive or post-procedure skin prefer a mask that is hydrating and calming with ingredients like allantoin, bisabolol, aloe, avocado or meadowfoam.

Anti-aging firming mask formulas will include botanicals such as meadowfoam seed extract, mushroom, pumpkin, growth factors or peptides.