What happens when you use fake sunscreen?

According to Dr. Nguyen Tien Thanh of the Vietnam Dermatology Association, sunscreen is an important "shield" protecting the skin from the harmful effects of ultraviolet (UV) rays. Using counterfeit or low-quality products not only wastes money but also exposes users to the risk of severe sunburn, premature aging, and skin cancer.

A standard sunscreen must contain skin-protecting active ingredients, including chemical agents such as avobenzone, octocrylene, and Tinosorb S/M which absorb UV rays, and physical agents such as zinc oxide and titanium dioxide which reflect and scatter UV rays away from the skin.

Some counterfeit or illegally imported sunscreens may not contain sufficient or correct sun-protective ingredients, may be adulterated with harmful substances such as high concentrations of parabens, banned fragrances, industrial alcohol, or may have inaccurate SPF/PA ratings, misleading users about their protective effectiveness. As a result, UV rays still penetrate the skin, causing serious damage.

There are two types of UV rays that cause sunburn: UVA and UVB. UVA rays, also known as long-wavelength rays, account for about 95% of the UV radiation that reaches the skin. Both UVA and UVB are harmful to the skin, but UVA rays are a greater threat because the majority of them reach the Earth's surface.

One of the most common harmful effects is acute sunburn, causing redness, burning, and blistering of the skin after just a few minutes of sun exposure. The skin can also develop melasma and post-inflammatory hyperpigmentation due to UVA rays penetrating deep into the dermis, stimulating melanocytes to increase melanin production. UVA increases enzymes that destroy collagen and elastin, causing premature wrinkling and sagging. In particular, UVB rays can cause gene mutations, while UVA rays create free radicals that attack DNA, increasing the risk of squamous cell carcinoma or melanoma – the most dangerous type of skin cancer.

In reality, distinguishing between genuine and counterfeit sunscreen with the naked eye is nearly impossible. Counterfeit products today are very sophisticated, from packaging and color to scent. Even medical professionals need spectroscopic analysis, SPF/PA quantification, or laboratory testing to evaluate the product.

To effectively protect your skin, users should prioritize reputable brands approved by the Ministry of Health , choose products with transparent clinical studies, and clearly published SPF test results. Consumers should purchase products from authorized distributors and avoid buying counterfeit or unofficial products. For skin after laser treatments, peels, or microneedling, choose sunscreens specifically designed for sensitive skin, free of alcohol and fragrance.

Dr. Thanh recommends choosing the appropriate SPF/PA for each activity, specifically:

Dosage: 1-1.25 ml for face and neck (2 mg/cm² of skin).

Application time: 15-30 minutes before sun exposure.

Reapplication frequency: Every 2-3 hours if outdoors, sweating, or swimming; every 4-6 hours if working indoors.

Source: https://baohatinh.vn/dieu-gi-xay-ra-khi-dung-kem-chong-nang-gia-post289483.html