Every summer brings with it sunshine, and more SPF myths than you ever asked for. This video breaks down 7 of the top sunscreen myths I see around.

I’ve listed the references under each myth here, along with where I’ve covered it before (if applicable). Note: not all references are equally good, and in general you shouldn’t just take the word of a paper just because it’s been published in a peer-reviewed journal.

The free sample chapter on sunscreen from The Lab Muffin Guide to Basic Skincare can be downloaded here: The Lab Muffin Guide to Basic Skincare

I covered some other skincare myths in a video recently as well: Biggest Skincare Myths – and What to Do Instead (video)

1. “SPF 50 is only a little bit better than SPF 30.”

Covered before in my post here: Video: What Does SPF Mean? Is High SPF Sunscreen Better?

• Herzog SM et al., JAMA Dermatol 2017, 153, 348-350. DOI: 10.1001/jamadermatol.2016.4924
• Russak JE et al., J Am Acad Dermatol 2010, 62, 348–349. DOI: 10.1016/j.jaad.2009.05.025 (open access)
• Williams JD et al., J Am Acad Dermatol 2018, 78, 902–910. DOI: 10.1016/j.jaad.2017.12.062 (open access)
• Pruim B & Green A, Australas J Dermatol 1999, 40, 14-18. DOI: 10.1046/j.1440-0960.1999.00309.x

2. “DIY sunscreen is effective.”

Covered before in my post here: Don’t Get Burnt by DIY Sunscreen

• Realize Beauty, The Trouble With Making Your Own Sunscreen
• Kobo Products, Perspectives on Supplying Attenuation Grades
• BASF Creations Newsletter, Formulating with Zinc Oxide

3. “Wearing sunscreen is worse for you than not wearing sunscreen.”

I highly recommend reading this very recent open access review, which summarises the reasoning for the position taken by health authorities from different disciplines in Australia and New Zealand:

• Whiteman DC et al., When to apply sunscreen: a consensus statement for Australia and New Zealand (open access), Aust NZ J Public Health 2019, online; DOI: 10.1111/1753-6405.12873.

I cover the two main reasons for this myth in this video:

“Sunscreen ingredients are harmful”

Hormonal effects:

• Schlumpf M et al., In vitro and in vivo estrogenicity of UV screens (open access), Environ Health Perspect. 2001, 109, 239–244. DOI: 10.1289/ehp.01109239
• Axelstad M et al., Effects of pre- and postnatal exposure to the UV-filter octyl methoxycinnamate (OMC) on the reproductive, auditory and neurological development of rat offspring, Toxicol Appl Pharmacol. 2011, 250, 278-90. DOI: 10.1016/j.taap.2010.10.031.
• Wang J et al., Recent advances on endocrine disrupting effects of UV filters (open access), Int J Environ Res Public Health. 2016, 13, E782. DOI: 10.3390/ijerph13080782
• Wang SQ et al., Safety of oxybenzone: putting numbers into perspective, Arch Dermatol. 2011, 147, 865-6. DOI: 10.1001/archdermatol.2011.173.

Nanoparticles:

• Therapeutic Goods Administration, Literature review on the safety of titanium dioxide and zinc oxide nanoparticles in sunscreens: Scientific review report, Aug 2016

“The sun is good for you”

General:

• Lindqvist PG et al., Avoidance of sun exposure as a risk factor for major causes of death: a competing risk analysis of the Melanoma in Southern Sweden cohort (open access), J Intern Med. 2016, 280, 375-87. DOI: 10.1111/joim.12496.
• Scragg R et al., Association of sun and UV exposure with blood pressure and cardiovascular disease: A systematic review, J Steroid Biochem Mol Biol. 2019, 187, 68-75. DOI: 10.1016/j.jsbmb.2018.11.002
• Lindqvist PG & Landin-Olsson M, The relationship between sun exposure and all-cause mortality, Photochem Photobiol Sci. 2017, 16, 354-361. DOI: 10.1039/c6pp00316h

Vitamin D:

• Kannan S & Lim HW, Photoprotection and vitamin D: a review (open access), Photodermatol Photoimmunol Photomed. 2014, 30, 137-45. DOI: 10.1111/phpp.12096.
• Marks R et al., The effect of regular sunscreen use on vitamin D levels in an Australian population. Results of a randomized controlled trial, Arch Dermatol. 1995, 131, 415-21. DOI: 10.1001/archderm.1995.01690160043006

Nitric oxide:

• Opländer C et al., Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates, Circ Res. 2009, 105, 1031-40. DOI: 10.1161/CIRCRESAHA.109.207019.

Health benefits of sunscreen:

• Geller AC et al., Interdisciplinary perspectives on sun safety (open access), JAMA Dermatol. 2018, 154, 88-92. DOI: 10.1001/jamadermatol.2017.4201.
• American Cancer Society, Key Statistics for Melanoma Skin Cancer, 4 Jan 2018
• A Green et al., Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial, Lancet 1999, 354, 723–729.
• A Green et al., Reduced melanoma after regular sunscreen use: randomized trial follow-up, J Clin Oncol 2011, 29, 257–263.
• JC van der Pols et al., Prolonged prevention of squamous cell carcinoma of the skin by regular sunscreen use (open access), Cancer Epidemiol Biomarkers Prev 2006, 15, 2546–2548.
• S Darlington et al., A randomized controlled trial to assess sunscreen application and beta carotene supplementation in the prevention of solar keratoses, Arch Dermatol 2003, 139, 451–455.
• MC Hughes et al., Sunscreen and prevention of skin aging: a randomized trial, Ann Intern Med 2013, 158, 781–790.
• R Ghiasvand et al., Sunscreen Use and Subsequent Melanoma Risk: A Population-Based Cohort Study, J Clin Oncol 2016, 34, 3976-3983

4. “Chemical sunscreen only works if you apply it to bare skin.”

This was also covered in this video: All Your Sunscreen and Make-up Questions Answered

Blog post: Why Do I Need to Apply Sunscreen Before Sun Exposure?

DM Beyer et al., Clothing reduces the sun protection factor of sunscreens, Br J Dermatol 2010, 162, 415-419

5. “Make-up with SPF gives adequate sun protection.”

Also covered in How SPF Changes With How Much Sunscreen You Use and All Your Sunscreen and Make-up Questions Answered

B Petersen & HC Wulk, Application of sunscreen–theory and reality, Photodermatol Photoimmunol Photomed 2014, 30, 96-101

6. “Layering products with SPF doesn’t increase SPF.”

• Pruim B & Green A, Photobiological aspects of sunscreen re-application, Australas J Dermatol 1999, 40, 14-8. DOI: 10.1046/j.1440-0960.1999.00309.x

7. “You don’t need to reapply sunscreen if you haven’t been in the sun the whole time.”

This was discussed in Chemical vs Physical Sunscreens: The Science (with video)

If you liked this video, you might also be into my other posts on sunscreen:

What Does SPF Mean? The Science of Sunscreen

My Sunscreen Mini-Review Spreadsheet

Is Your Sunscreen Killing Coral? The Science (with Video)

Product Rant: SPF Sunscreen Drops