Sunscreen Guide: What is Sun Protection Factor (SPF)? What SPF should I use? How to Apply Sunscreen?
31 July 2026
What is Sun Protection Factor (SPF)?
SPF is a rating system that indicates how long a product can protect the skin from harmful sun rays. The SPF number indicates how long the product can provide protection against UVB rays. For example, an SPF 30 sunscreen can protect your skin about 30 times longer than if it were unprotected. However, this duration is not constant; it can vary depending on factors such as the amount of product applied, sweating, swimming, and frequency of reapplication.
What does SPF do?
SPF helps prevent the harmful effects of UVB rays, which cause sunburn. Modern sunscreens protect not only against UVB rays but also against UVA rays, which cause premature skin aging. According to scientific research, regular SPF use can reduce the risk of skin cancer and slow down photoaging.
What SPF should sunscreen be?
A minimum of SPF 30 is recommended for daily use. While SPF 30 blocks approximately 97% of UVB rays, SPF 50 increases this rate to over 98%. Although the difference may seem small, SPF 50 should be preferred, especially for skin prone to hyperpigmentation or sensitive skin. Individuals with a history of skin cancer or a weakened immune system should use higher-factor products.
What is the difference between SPF 30 and SPF 50?
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SPF 30: Provides approximately 96.7% UVB protection.
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SPF 50: Offers close to 98% UVB protection.
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SPF 100: Provides approximately 99% UVB protection.
Although the difference may seem small, SPF 50 is a safer option for those with high sun sensitivity, eczema patients, or children.
SPF 50+ products
Sunscreen Recommendations
Eva Maree 3D Melani Sun Lotion SPF 50+ protects the skin not only from the sun's harmful UVA/UVB rays but also from blue light (HEV) and infrared (IR) rays from screens. With its Ectoin and blue microalgae content, it neutralizes free radicals, strengthens the skin barrier, and can be safely used on skin prone to hyperpigmentation and sensitive skin.
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Broad-spectrum protection against UVA, UVB, HEV (blue light), and IR rays
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Antioxidant support with Ectoin + blue microalgae
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100% vegan, cortisone-free, dermatologically tested
Click on the title to review the product in detail.
How to apply sunscreen? What is the correct sunscreen application?
A single application in the morning does not provide all-day protection; it needs to be reapplied regularly.
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Should be applied 20–30 minutes before sun exposure.
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Approximately 1 teaspoon of product should be used for the face.
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Should be reapplied every two hours or after sweating and swimming.
When applying sunscreen, attention should also be paid to frequently missed areas such as behind the ears, neck, and around the eyes.
What to consider when choosing sunscreen?
When choosing a sunscreen, skin type, product content, and SPF value should be considered:
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Oily skin: Water-based, mattifying, and non-comedogenic products
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Dry skin: Cream formulas with high moisturizing properties
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Sensitive skin: Fragrance- and alcohol-free, mineral filter sunscreens
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Skin with hyperpigmentation tendency: Products containing anti-spot ingredients and providing at least SPF 50 protection are recommended.
In special skin conditions such as sensitivity, acne tendency, or atopic dermatitis, the choice should be made according to a dermatologist's recommendation. Click here to review our non-comedogenic sunscreen selection guide.
What is the difference between mineral filter and chemical filter sunscreens?
Both filters can be effective; however, the correct choice should be made according to skin type.
Mineral Filter Sunscreens
Provides protection by physically reflecting UV rays thanks to ingredients like zinc oxide and titanium dioxide. Especially suitable for sensitive skin.
Chemical Filter Sunscreens
Absorbs UV rays, rendering them harmless. It has a lighter texture and can be easily applied under makeup.
How long does sunscreen protect?
The effectiveness of sunscreens decreases over time.
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Should be reapplied approximately every two hours.
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Non-waterproof products should be reapplied after swimming.
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For reapplication during the day on made-up skin, spray formulations or tinted sunscreens can be used.
What SPF should children use? SPF guide by age
Babies and Children
For babies over 6 months, fragrance-free and mineral filter SPF 50 should be used. Click here to review Minois Paris products, produced in France for the delicate skin of babies and children.
Teenagers
Non-comedogenic products are recommended, especially for acne-prone skin that appears during adolescence.
Adults
SPF 50+ should be preferred for those experiencing photoaging or hyperpigmentation problems.
Elderly
Due to thin skin structure and risk of hyperpigmentation, products providing high protection should be used.
Should people with skin cancer use SPF? Should people with skin cancer use sunscreen?
Continuous use of high SPF products provides significant protection, especially for individuals at risk of skin cancer. According to research by the American Academy of Dermatology, regular SPF use reduces the risk of developing melanoma. It also plays an effective role in preventing photoaging symptoms such as wrinkles, loss of elasticity, and hyperpigmentation.
Should people with eczema use SPF? How to use sunscreen for skin problems?
Eczema (Atopic Dermatitis)
Fragrance-free and alcohol-free mineral filter products should be preferred. Click here to review our article where you can get detailed information about eczema.
Hyperpigmentation Problems
SPF 50+ products containing UVA protection and supported by anti-spot active ingredients should be used.
History of Skin Cancer
High-factor, broad-spectrum sunscreens should be used daily, year-round.
Anti-aging Care
SPF products supported with ingredients like Vitamin C and Niacinamide provide additional protection against signs of aging. Click here to review our article where you can get detailed information about the anti-aging effects of antioxidants.
Frequently Asked Questions
What is Sun Protection Factor (SPF)?
SPF is a measure indicating how long the skin can be protected from UVB rays from the sun. For example, SPF 30 provides approximately 30 times longer protection for the skin compared to an unprotected state. However, this duration varies depending on the amount of product, sweating, swimming, and frequency of reapplication.
Which SPF value should be preferred?
A minimum of SPF 30 is recommended for daily use. SPF 30 blocks 96.7% of UVB rays, while SPF 50 blocks approximately 98%. Although the difference may seem small, SPF 50 is safer for skin prone to hyperpigmentation, sensitive skin, or children's skin. Higher-factor products should be used by individuals with a history of skin cancer or a weakened immune system.
How to apply sunscreen correctly?
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It should be applied 20–30 minutes before sun exposure.
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Approximately 1 teaspoon of product is sufficient for the face and neck (this amount will be equivalent to about 2 fingers of sunscreen).
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It should be reapplied every 2 hours and after swimming/sweating.
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Frequently missed areas such as behind the ears, neck, and around the eyes should not be forgotten.
This article was written by Pharmacist Nil Eker from the Primum Pharma team.