New Delhi, May 4 (IANS): Doctors have time and again harped on the importance of using a sunscreen to protect one's skin. For many, however, choosing the right sunscreen is a tough choice, what with scores of products with various SPFs (Sun Protection Factors) flooding store shelves.

Does higher SPF mean better protection? Not so much, say doctors, who warn against being misled by marketing gimmicks.

"SPF is a log measurement of protection against the sun's rays. Although you may be led to believe that a higher SPF sunscreen will give you better protection, the difference in effectiveness between a lower and higher SPF lotion is not much. For example, the difference in the efficacy between an SPF 15 and 30 sunscreen is just 1.2 percent," Nitin S. Walia, consultant, dermatology at Max Super Speciality Hospital, told IANS.

What actually does make a difference is the amount of sunscreen lotion or cream that you dab on, he added.

Surabhi Patel, dermatologist, agrees: "One should apply generous amounts of sunscreen on all exposed parts of the body, at least 15 minutes before stepping out in the sun, for its effectiveness to kick in."

"Also, considering the Indian climate, one tends to perspire a lot in the heat. So re-application of sunscreen lotion or cream every two hours is important," Patel said.

The same rules apply when you are going for a dip in the pool -- apply generous amounts of sunscreen and re-apply every two hours.

"Consumers should be aware that no sunscreen is waterproof, because ultimately all such creams get washed off. They can be water resistant, but those that are labelled so should also state whether they remain effective for 40 minutes or 80 minutes when swimming or if you perspire. Also there should be directions on when to re-apply," Patel said.

Talking about the benefits of sunscreen products, dermatologist Bindu Sthalekar said, "Many people think that sunscreen is only to guard against tanning. However, over- exposure to sun and sun damage can lead to premature ageing, dullness, pigmentation, and fine lines. Applying an SPF 15 suncreen means you can stay out in the sun for 50 minutes or roughly two hours without any skin damage".

While doctors advise sunscreen in all seasons, the efficacy of physical protection is given great importance by all.

"Large amounts of sunscreen would ideally be needed to protect oneself the whole day, and carrying around so much sunscreen may not be feasible," Walia said. "This is why physical protection, like a scarf or dupatta, long sleeved clothes, an umbrella, a pair of shades, is important because they screen you from the sun's direct rays".

Protection of your hair with a head gear or hat is also important.

And doctors advise limited time outdoors between 10 a.m. and 2 p.m. when the sun's rays are the strongest.

So guard yourself and bask in the sun, literally!