The sun can be fun… until sunburn strikes. Our skin reddens, swells, and stings, and may even blister or give us a fever. Sunburn lasts for days or even weeks. For those seeking relief, CBD may have the potential to soothe sunburned skin.
What is Sunburn?
Sunburn occurs due to overexposure to ultraviolent radiation (UVR), either from the sun or sunlamps/tanning beds. Although the precise chemical mechanisms underlying sunburn remain elusive, it is clear that UVR damages the DNA in our skin cells. [1-5, 13-15] This damage spurs several reactions, and we call those reactions sunburn.
Sunburned skin synthesizes proteins such as cytokines, which generate inflammation; CXCL5 specifically has been connected to the pain and inflammation from sunburn.  Cutaneous blood vessels dilate, generating redness.  TPRV ion channels, which contribute to heat sensation, have also been implicated in sunburn pain.  As a means of protecting against malignant metamorphosis (i.e. cancer), skin cells may induce apoptosis and die; this shows up as peeling skin. [2,5]
Can CBD Help with Sunburn?
There are not yet any studies on CBD for sunburn. However, our skin has its own endocannabinoid systemdesigned to maintain the equilibrium, immunity, and health of skin cells.  CBD has several skincare properties that make it a promising option for sunburn:
- Inflammation: CBD has been shown to reduce skin inflammation in humans. [7,8] This may be due to cytokine and TRPV ion channel modulation. 
- Pain: Reducing inflammation helps with pain. But topical CBD also has analgesic properties against neuropathic pain since it interacts with CB1 and CB2 receptors in the skin. [6,9]
- Antibacterial: CBD has demonstrated antimicrobial properties.  Blisters from sunburn may lead to serious infection, making topical anti-bacterial agents potentially helpful.
- Antioxidant: CBD is an antioxidant.  Researchers have suggested that oxidative damage may facilitate the cellular reactions associated with sunburn. 
CBD products formulated to moisturize and soothe skin are important; the American Academy of Dermatology recommends using a moisturizer after a cool shower to trap water in the skin. 
Should I Seek Medical Attention for my Sunburn?
Sunburn is very common, affecting roughly 37% of adults and 55% of youths at least once a year.  But it can be quite serious; in 2013, emergency department visits at US hospitals due to sunburn were estimated to cost over $11 million. 
The Mayo Clinic recommends seeking medical attention if sunburn symptoms do not improve after a few days. Other signals to seek medical attention are major blistering, high fever, extreme pain, and blister infection. 
- Berman, K., & Cunningham, L. (Eds.). (2019). Sunburn. University of Rochester Medical Center. Retrieved from https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=P00317
- Dawes, J. M., et al. (2011). CXCL5 mediates UVB irradiation-induced pain. Science Translational Medicine,3(90). doi:10.1126/scitranslmed.3002193
- Sobell, J. M. (2019). What happens when you get a sunburn? Scientific American. Retrieved from https://www.scientificamerican.com/article/what-happens-when-you-get/
- Moore, C., et al. (2013). UVB radiation generates sunburn pain and affects skin by activating epidermal TRPV4 ion channels and triggering endothelin-1 signaling. Proceedings of the National Academy of Sciences,110(34). doi:10.1073/pnas.1312933110
- Murphy, G., et al. (2001). The molecular determinants of sunburn cell formation. Experimental Dermatology,10(3), 155-160. doi:10.1034/j.1600-0625.2001.010003155.x
- Oláh, A., et al. (2014). Cannabidiol exerts sebostatic and antiinflammatory effects on human sebocytes. Journal of Clinical Investigation,124(9), 3713-3724. doi:10.1172/jci64628
- Bíró, T., et al. (2009). The endocannabinoid system of the skin in health and disease: Novel perspectives and therapeutic opportunities. Trends in Pharmacological Sciences,30(8), 411-420. doi:10.1016/j.tips.2009.05.004
- Fumagalli, M., et al. (2017). Anti-inflammatory activity of Cannabis sativa L. extracts in an in vitro model of skin inflammation. 65th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA 2017). doi:10.1055/s-0037-1608567
- Jhaveri, M. D., et al. (2009). Endocannabinoid metabolism and uptake: Novel targets for neuropathic and inflammatory pain. British Journal of Pharmacology,152(5), 624-632. doi:10.1038/sj.bjp.0707433
- Appendino, G., et al. (2008). Antibacterial Cannabinoids from Cannabis sativa: A Structure−Activity Study. Journal of Natural Products,71(8), 1427-1430. doi:10.1021/np8002673
- Hampson, A. J., et al. (1998). Cannabidiol and D-9-tetrahydrocannabinol are neuroprotective antioxidants. Proceedings of the National Academy of Sciences,95(14), 8268-8273. doi:10.1073/pnas.95.14.8268
- How to treat sunburn. (2018). American Academy of Dermatology. Retrieved June 6, 2019, from https://www.aad.org/public/skin-hair-nails/injured-skin/treating-sunburn
- Holman, D. M., et al. (2014). The association between demographic and behavioral characteristics and sunburn among U.S. adults — National Health Interview Survey, 2010. Preventive Medicine,63, 6-12. doi:10.1016/j.ypmed.2014.02.018
- Guy, G. P., et al. (2017). Estimated cost of sunburn-associated visits to US hospital emergency departments. JAMA Dermatology,153(1), 90. doi:10.1001/jamadermatol.2016.4231
- Mayo Clinic Staff (2018). Sunburn. Mayo Foundation for Medical Education and Research. Retrieved from https://www.mayoclinic.org/diseases-conditions/sunburn/symptoms-causes/syc-20355922