How Long Does Sunscreen Last on Skin? Experts Insight

Updated Date: by Reet Patel

According to Hopskinmedicine, the maximum time a sunscreen lasts on your skin and protects it from the scorching excessive heat and cancerous moles is two hours.

So is it harmful to stay in the sun after post-two hours?  What if you apply an expired sunscreen?

This article is an answer to all such questions and other concerns related to sunscreen, application, and factors to consider.

Now that you know how long does sunscreen lasts on the skin, let’s get a wealth of information?  After all, your skin deserves tenderness, love, and care.

Reasons to Reapply Sunscreen After Two Hours

Since sunscreens last for two hours post-application, it becomes necessary to recoat your face with sunscreen.

On the other hand, if you are swimming or sweating, the frequency of reapplying sunscreen increases.

Another reason that urges you to reapply is the use of chemical sunscreens.  It breaks down easily when exposed to the sun, which is why you must keep an eye on, it and reapply frequently.

Lastly, you might commit a mistake in reapplying for the first time, which is why it becomes necessary to reapply.  It’s similar to how you color walls; painting it for the first time and then recoating it for the final touch-up to avoid missing out on spots or areas.

Now that you know the need to reapply sunscreen, let’s know what if you don’t follow the regimen.  In short, what could be the challenges to be prepared for?

Consequences of Not Reapplying Sunscreen

Since sunbathing is one of your favorite activities (or maybe you’re seeking information just to stay protected from the sun), it becomes imperative to know what to do if you skip applying or reapplying sunscreen.

The last thing that happens when letting your skin be exposed to the sun is skin cancer.  But before that, there are many other consequences you must not neglect.  These are:

Painful Burns

does sunscreen last all day

Sunburn is a condition where you notice red, painful skin.  It happens when you neglect to apply sunscreen and remain in the sun for too long.  It happens with most people, who due to their busy schedule, forget to re-apply sunscreen.   If the painful burns are neglected, they turn to blistering, which is when you will require to consult skincare experts and use the best skin care products.

Signs of Aging

should sunscreen be applied last

Your young, tight, and wrinkle-free skin is just a few days away from looking old and saggy if you’re skimping on sunscreen.  Too much UV exposure can damage your skin’s collagen production, which is responsible for tightening your skin.  As a result, there is a loss in skin elasticity and visible wrinkles.

Dark Spots/Hyperpigmentation

does sunscreen work immediately

Melanin is a natural pigment that offers skin, hair, and eyes their natural color.  Any imbalance or spike in melanin can disturb the color of your skin, hair, and eye.  One of the factors that zoom up melanin is unprotected exposure to the sun, which results in hyperpigmentation or dark spots.

Skin Cancer

how long after applying sunscreen can i swim

Lastly, the risk of skin cancer is always behind you if your skin is exposed to the sun.  When there is direct sun exposure, the skin cells grow abundantly.  According to the study by the Skin Cancer Foundation, wearing sunscreen daily slows down the development of squamous cell carcinoma by 40% and melanoma risk by 50%.

So these are the challenges you could face if not applying sunscreen.  Now that you know that sunscreen is mandatory, let’s know everything about it.

What is the Minimum SPF Requirement According to Dermatologists?

As per the study by the American Academy of Dermatology, the minimum sun protection factor (SPF) should be at least SPF 30 or more.  Also, it should be applied half an hour before stepping outside and must be reapplied every two hours.

Before knowing the different sun protection levels, you must know that the SPF rating does not indicate the percentage of protection.  It means a high SPF (for instance 100) doesn’t mean your skin is 100% protected against the sun’s heat.

Here is the list of sun protection levels:

  • SPF 15 – Blocks 93% UVB rays
  • SPF 30 – Blocks 97% UVB rays
  • SPF 40 – Blocks 97.5% UVB rays
  • SPF 50 – Blocks 98% UVB rays
  • SPF 70 – Blocks 98.5% UVB rays
  • SPF 100 – Blocks 99% UVB rays

With this, let us also tell you how long each sunblock lasts in the sun?

How Long Does SPF 15 Last?

Generally, it depends on how long your skin survives in the sun.  For instance, if your skin remains unburnt in the sun for about 10 minutes without sunscreen, you can expect to live in the sun for about 150 minutes once you apply sunscreen (SPF 15).  In other words, SPF 15 is responsible to protect your skin from the sun about 15 times.

How Long Does SPF 30 Last?

If you bring home a bottle of sunscreen with SPF 30, then be prepared to stay protected in the sun for almost 300 minutes, i.e., 5 long hours.  You can even take a sunbath after wearing this sunscreen. However, do not forget to reapply sunscreen every two hours.

How Long Does SPF 40 Last?

The difference between SPF 30 and 40 is that the latter protects 0.5% more than the former.  It means you get an additional 0.5% of the sun protection with SPF 40 than with SPF 30.  If the SPF 30 gives 97% sun protection, the SPF 40 offers 97.5% sun protection.

How Long Does SPF 50 Last?

You can expect 98% sun protection with SPF 50, meaning you stay protected from sun damage 50x more than the other sunscreens.

How Long Does SPF 70 Last?

There is a marginal difference between SPF 50 and SPF 70.  It may compel you to stay for a longer time in the sun, but it doesn’t guarantee the same level of protection.  Therefore, it is advisable to apply sunscreen ranging between SPF 15 to 50.

How Long Does SPF 100 Last?

Just like SPF 70, the SPF 100 also ensures minor protection from the scorching heat.  It doesn’t bring a world of difference or doesn’t promise to keep you protected for 24 hours.  Even after applying SPF 100, you are required to coat your face with sunscreen every two hours.

Apart from the sun protection level, you might also want to know how much sunscreen to use per application?

A liberal application is a 1-fluid ounce, which is enough for protecting your face from sunburns and ultraviolet radiation.  On the other hand, if you want to cover your whole body, a shot glass would suffice.

Now that you know the minimum requirement along with the amount to use, let’s look at some of the vital factors.

Things to Consider When Buying Sunscreen

how long does it take sunscreen to absorb

You cannot simply bring any ordinary sunscreen and slather on your face.  There are a few factors that need to be taken into consideration.  So what are those and how are they important?

Keep on reading to know more about them:

Broad Spectrum

Broad-spectrum is one of the factors to consider when buying since it protects your skin from both UVA and UVB rays.  UVA rays are a primary cause of wrinkles while UVB burns the skin.  Also, exposure to both UV rays increases the chances of skin cancer.  Therefore, buy sunscreens labeled as broad-spectrum to shield your skin from UV radiation.

Water-Resistant Sunscreen

Since you would be swimming or sweating, you need waterproof sunscreen.  With such water-resistant sunscreen, the risk of dripping off or sticky skin is zero.

How Long Does it Take Sunscreen to Absorb?

The answer to the question depends on what type of sunscreen you are using.  For instance, physical sunscreens do not require waiting or an advance application process.  You apply it right before stepping out and it works.  On the flip side, chemical sunscreens do come with a waiting period.  It means you need to apply 15-20 minutes before going out in the sun.  During this time, the sunscreen penetrates and prepares your skin to protect against the sun’s rays.

Types of Sunscreen

There are two types of sunscreen: Physical & Chemical.

Physical Sunscreen

Physical sunscreen, aka mineral sunscreen, consists of zinc oxide and titanium dioxide.  These ingredients are approved by the Food and Drug Administration.  These ingredients create a protective barrier on your skin’s surface.  According to the study by Wiley, mineral sunscreens absorb 95% of the UV rays. The drawback of mineral sunscreen is it leaves white cast post-application.

Chemical Sunscreen

Chemical sunscreen ingredients include oxybenzone, octisalate, octocrylene, homosalate, octinoxate, and avobenzone.  Unlike physical sunscreens, chemical sunscreens require wearing it 15-20 minutes prior to stepping outside to protect by absorbing UV rays.  The USP of chemicals is it converts ultraviolet radiation to heat so that it doesn’t harm your skin.

Expired Sunscreen

When buying a bottle of sunscreen, you must check the expiration date on it.  Generally, sunscreen lasts for three years from the date of manufacturing.  Pick a sunscreen labeled with an expiration date for a quick idea of the shelf life.


1. How Long Does Sunscreen Last Once Applied?

No matter which type of sunscreen you apply, it lasts for up to two hours. Also, no matter which season you are entering, it is still advisable to carry the same bottle of sunscreen that you would be using in the summer.

2. Does Sunscreen Last All Day?

It all depends on where you spend most of the time. However, no sunscreen claims to last for a full day. It’s just the application time decreases. For instance, if you are indoors and haven’t taken a shower or sweated, your sunscreen probably may last for about four to six hours.

3. Should Sunscreen Be Applied Last?

The application process depends on the types of sunscreen you are using. For instance, if you are using a physical one, you must apply it after using a moisturizer in your morning routine. On the other hand, if it is a chemical one, make sure you apply it at the beginning so that it can penetrate the skin.

4. Does Sunscreen Work Immediately?

Although sunscreen starts protecting your skin from ultra-radiation as soon as applied, it still takes around 10-15 minutes to fully protect. It is believed that the sunscreen takes time to sink into the skin and then starts absorbing heat.

5. How Long After Applying Sunscreen Can I Swim?

The golden rule is to apply sunscreen 30 minutes prior to swimming. This way, it gets time to penetrate the skin and absorb efficiently.

6. Does Sunscreen Expire?

According to the Food & Drug Administration, sunscreens remain effective for at least three years from the date of manufacturing. However, you must discard sunscreen past its expiration date or any obvious changes in color or consistency. Sometimes you may also buy sunscreens without expiration dates, in that case, you can write the purchase date on them.


Sunscreen expires and becomes less effective as it ages. A lot of people don’t know this, but sunscreen has a shelf life of up to three years from the time you buy it.  Sunscreen is important, but how long does it last?

Most sunscreens last about two hours before needing reapplication. You should also consider that most people don’t apply enough sunscreen and suffer from brown spots and sunburn.


Published Date: Jan 18, 2022

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