Natural sunscreens (including oral supplements and plant oils) haven’t been proven to have a direct effect on the protection of your skin when faced with the sun’s damaging effects. There are some examples that could be combined with proven sun-protection methods (sunscreen, clothing, shade) to offer extra sun protection. However, zinc oxide and titanium dioxide are two natural ingredients that have shown to have UV-protective abilities.

The skincare industry has made an outstanding $5.6 billion in sales in only in 2018. The brands that were labeled as “natural” were the most popular and were the top contributors to market growth.

Also, some plant oils, extracts, and supplements have gained popularity as potential natural alternatives to replace commercial sunscreen products. The question is, are they effective?

Ultraviolet Radiation

An enormous exposure to solar radiation can lead to both skin aging and skin cancer. The ultraviolet (UV spectrum) is the most dangerous since its wavelength is shorter than that of visible light but longer than X-rays.

The main bad guys are UVA and UVB radiation. UVA is responsible for 95% of UV rays reaching Earth’s surface and UVB for 5%. Together, they can cause sunburns, DNA damage, and accelerate skin aging according to the studies done by Sérgio Schalka in “Brazilian Consensus on Photoprotection”.

When used in the right way and the right amount, sunscreens can reduce sun-induced skin aging (photoaging) and reduce the risk of skin cancer.

Can Plant Oils Act as Sunscreen and Protect You?

First of all, it’s recommended that you use a broad-spectrum sunscreen (i.e., UVA + UVB protection) with a sun protection factor (SPF) of 30, at minimum, or 40 if get burned easily.

So, are natural plant oils effective? The answer is, unfortunately, not really, at least when they are used alone.

The plant oils used for testing on protection against just UVB radiation showed that they provide an SPF of <8. These oils can be included in the commercial sunscreen products to boost the overall SPF rating, but on their own, they don’t offer much UV protection.

Reliability could also be a problem with plant-based formulas that are home-made. Sunscreens are made using specific ingredients in specific amounts, while also balancing manufacturing methods to help ensure these UV-protective ingredients are evenly distributed in the sunscreen. This process is nearly impossible to duplicate at home.

Also, some of these plant oils can cause allergic reactions or skin irritation to some people. Although these reactions can be mild, there is a risk of it becoming a serious problem.
In some cases, when SPF against both UVB and UVA is measured, the values can drop extremely low. For example, coconut oil offers an SPF of 7 for just UVB, but an SPF of ≤1 against UVA + UVB.

Plant oils alone should not be used to completely replace sunscreen, as they do not provide the right protection. However, they may be used as an ingredient in some sunscreens to help the overall SPF rating of the product.

Can Supplements Protect You?

Cocoa as Sunscreen

While using specially processed high-flavanol cocoa powders or chocolate, three RCTs (almost all in females with Fitzpatrick skin types 2 or 3) noticed a slight improvement when it came to the skin’s ability to resist UV damage after 6 weeks of supplementation.
These results were consistent during the test trials. As further trials get published, you should keep an eye on this supplement.

Polypodium leucotomos as sunscreen

In the trials done on both humans and animals, Polypodium leucotomos (P. leucotomos) has proved to be able to reduce UV-caused skin cell damage, DNA damage, and oxidative stress.  In the human trials, both short (<1 week) and long-term (1- to 3-month) trials have had promising results.
The only setback is that nearly all of these studies were conducted in people with Fitzpatrick skin types 1–3. The effects of P. leucotomos on skin types 4–6 haven’t been studied enough for now.

A note of caution — the estimated SPF protection of P. leucotomos is ≈4. This is below the recommended level of at least 30, so therefore it should not be used to replace sunscreen.

Astaxanthin as sunscreen

Astaxanthin is regarded as a powerful antioxidant and it can reduce DNA damage caused by UV radiation. However, the research that has been done so far isn’t of the best quality. More thorough research is needed before steady results about its effectiveness come out.

Rosemary and Grapefruit Extract Combination as Sunscreen

Two promising human trials have studied a mix of rosemary and grapefruit extracts for UV protection.
A small pilot trial in 10 subjects was the first one and the second was a follow-up study that used random 90 subjects. In both trials, the result was the same. A combination of these two led to an increase in UV tolerance and reduced markers of oxidative damage in the skin.

Despite these promising results, the trials have been done on such limited data, so we should wait for more concrete results.

Vitamin E as Sunscreen

Although animal and cell studies have shown that vitamin E is a candidate for UV protection, human trials have given mixed (but promising) results for both topical applications and oral supplementation.

However, many studies have tested vitamin E as a part of a multi-ingredient formula, making it complicated to say what the effect could be if this vitamin was used alone.

We have come to the conclusion that supplements alone should not be used to fully replace sunscreen. Out of the ones that we have reviewed, Polypodium leucotomos has shown to be the most promising when it comes to UV protection.

What About Sunscreens Labeled as “Natural” or “Clean”?

In the US, the terms “clean” and “natural” are not clearly defined when it comes to skincare products. If these terms are included on the label it doesn’t offer any guarantees that the product is safer for consumers compared to products that don’t include these labels.

However, there are two natural sunscreen ingredients that have been proven useful: zinc oxide and titanium dioxide. They are referred to as physical-chemical barriers (aka inorganic chemical barriers or mineral sunscreens), these naturally occurring compounds function by reflecting and dissipating UV rays.

The terms “clean” and “natural” are unregulated in the US and don’t have any advantage over traditional sunscreen products. AS PROVEN, zinc oxide and titanium dioxide are two natural ingredients that have shown to have UV-protective abilities.

You should remember that there is no plant oil or extract that can replace sunscreen. Plant oils may be combined with sunscreens to boost their overall efficacy, but you should be careful cause they can also cause allergic skin reactions or irritations in some cases.

There is no single supplement that can fully replace sunscreen. Out of all the ones that have been studied, Polypodium leucotomos shows the greatest promise for UV protection when used together with sunscreen or other sun protection methods.