CBG May Help Skin Cells Respond to UVA Stress

Most conversations about cannabinoids and skin begin with CBD. A new laboratory study suggests that CBG may deserve more of the attention, especially when researchers examine how skin cells respond to ultraviolet A radiation.

Researchers from the Medical University of Białystok and the University in Białystok investigated how cannabidiol (CBD), cannabigerol (CBG), and a combination of the two affected human melanocytes after UVA exposure.¹ Melanocytes are the pigment-producing cells that make melanin. Although melanin helps protect surrounding tissue, these cells also experience oxidative and inflammatory stress when exposed to ultraviolet radiation.

The results did not show that CBD or CBG prevents sun damage. They did, however, show that the cannabinoids changed several interconnected systems governing antioxidant capacity, inflammation, membrane composition, and cellular signalling. CBG produced the clearest improvement in overall antioxidant capacity, while both cannabinoids influenced the lipid messengers through which cells coordinate stress responses.

That distinction is important. The research is less a story about a cannabinoid sunscreen and more a glimpse into how cannabinoids might eventually be used to influence the biological aftermath of UVA exposure.

Why UVA Stress Matters to Melanocytes

UVA radiation penetrates more deeply into skin than UVB and is strongly associated with oxidative stress and photoaging. Unlike a simple burn, oxidative stress involves unstable molecules that react with proteins, lipids, and other cellular components. If the stress is sustained or repeated, it can disrupt normal cell behaviour.

Melanocytes are especially interesting in this context. Their production of melanin is protective, but pigment synthesis can also generate reactive oxygen species. This means melanocytes must continually balance protection against the metabolic costs of responding to ultraviolet light.

Cell membranes are central to that balance. They are not passive walls. Their phospholipids provide structural stability and supply fatty acids that can be converted into eicosanoids, endocannabinoids, and other signalling molecules. Those molecules influence inflammation, antioxidant responses, proliferation, migration, and cell survival.

The new study therefore focused on lipid metabolism rather than asking only whether cells lived or died. This produced a more detailed picture of how CBD and CBG might alter a stressed melanocyte’s internal decision-making.

How Researchers Tested CBD and CBG

The researchers used primary human epidermal melanocytes obtained from a commercial cell supplier. The cells were exposed to UVA radiation at 365 nanometres and a dose of 18 joules per square centimetre. That exposure left approximately 75 percent of the cells viable, creating substantial stress without destroying the entire culture.

After irradiation, the cells were treated for 24 hours with 5 micromolar CBD, 1 micromolar CBG, or both. Matching groups of non-irradiated cells received the same treatments. Five independent samples were included in each experimental group.

The researchers then measured antioxidant status, membrane properties, fatty acids, lipid oxidation products, enzyme activity, inflammatory mediators, endocannabinoids, and receptor expression. This broader design matters because a compound can improve one pathway while leaving another unchanged or pushing it in an unwanted direction.

CBG Produced the Stronger Antioxidant Response

UVA exposure reduced the melanocytes’ total antioxidant status. CBG restored it, both alone and when combined with CBD. CBD alone did not produce a statistically significant restoration.

This is one of the study’s most useful findings because it prevents CBD’s familiarity from being mistaken for superiority. CBD remains the more commercially established ingredient, and its potential role in dermatology has generated a growing body of CBD skin health research. In this experiment, however, CBG appeared to be the primary contributor to the improved antioxidant capacity.

The combination also did not clearly outperform CBG alone. That weakens any easy appeal to an entourage effect. Combining cannabinoids can be biologically meaningful, but more ingredients do not automatically produce a stronger or more useful response.

Another result adds necessary restraint. UVA increased malondialdehyde, a marker created during the oxidation of polyunsaturated fatty acids. None of the cannabinoid treatments significantly reduced that marker compared with irradiated cells. In other words, CBG improved the cells’ overall antioxidant capacity without demonstrably reversing this particular sign of lipid damage.

That apparent split is not contradictory. Antioxidant capacity describes the resources available to resist oxidative stress, while malondialdehyde reflects damage that has already occurred. A compound can strengthen part of the defence system without undoing all downstream damage within 24 hours.

Cannabinoids Reshaped Inflammatory Signalling

The cannabinoids had pronounced effects on eicosanoids, signalling molecules derived from fatty acids. UVA increased several pro-inflammatory mediators, including PGE2, 5-HETE, and 12-HETE, while reducing the anti-inflammatory mediator 15-deoxy-PGJ2.

CBD, CBG, and their combination lowered the pro-inflammatory mediators in irradiated cells. CBD and the combined treatment also increased 15-deoxy-PGJ2. The treatments therefore shifted the lipid-messenger profile away from the pattern produced by UVA exposure.

The main findings can be summarized as follows:

• CBG produced the clearest restoration of antioxidant capacity.
• All three treatments reduced multiple pro-inflammatory lipid mediators.
• CBD and CBG partially normalized membrane lipid metabolism.
• No treatment significantly reduced the measured lipid peroxidation marker.

The same complexity appeared in phospholipid metabolism. UVA increased phospholipase A2 activity, an enzyme that releases fatty acids from membrane phospholipids. All cannabinoid treatments reduced this activity, with the combined treatment having the strongest effect. CBD preferentially helped restore phospholipid-bound DHA, while CBG increased phospholipid-bound arachidonic acid.

These differences suggest that CBD and CBG are not interchangeable antioxidants. They influence overlapping systems, but each appears to push parts of lipid metabolism in a distinct direction.

The Skin Has Its Own Cannabinoid Signalling Network

CBD and CBG were found primarily in the melanocytes’ membrane fractions. That location places them close to phospholipids, lipid-processing enzymes, and receptors involved in responding to the surrounding environment.

UVA changed the abundance and cellular distribution of CB1, CB2, TRPV1, and PPARγ receptors. CBG increased all four receptor types in irradiated and non-irradiated cells, while CBD had more selective effects. The treatments also changed levels of the endogenous signalling molecules anandamide, 2-AG, and PEA.

This supports a broader lesson emerging from cannabinoid dermatology research: skin contains a local signalling environment that can respond to cannabinoids without producing intoxication. The practical challenge is translating effects observed in isolated cells into formulations that penetrate the appropriate skin layers at a safe and reproducible dose.

That challenge also applies to other topical applications. Recent research into topical CBD for keloid scarring, for example, illustrates why promising molecular effects still require standardized formulations, penetration testing, and controlled human trials.

Why This Is Not Evidence for Cannabinoid Sunscreen

The experiment involved isolated melanocytes rather than intact human skin. Real skin contains keratinocytes, fibroblasts, immune cells, blood vessels, extracellular structures, and a barrier that affects whether a topical cannabinoid reaches melanocytes at all.

The researchers also used one UVA dose, one treatment period, and fixed cannabinoid concentrations. They did not test a consumer cream, measure protection during ordinary sunlight exposure, or determine whether repeated treatment is safe. Most importantly, the study did not demonstrate that CBD or CBG prevents melanoma.

Future work needs to progress through melanocyte and keratinocyte cocultures, reconstructed skin, animal studies where justified, and ultimately controlled human research. Researchers will also need to determine whether treatment is most useful before exposure, after exposure, or as part of a longer-term dermatological regimen.

Until then, cannabinoids should not be presented as substitutes for established photoprotection. The Canadian Dermatology Association’s sun-protection guidance recommends broad-spectrum, water-resistant sunscreen with SPF 30 or higher, alongside shade and protective clothing.

CBG Could Become a More Important Skincare Research Target

The commercial skincare market has largely been built around CBD, but the biological case for studying CBG is becoming harder to ignore. In this experiment, a lower concentration of CBG restored antioxidant capacity when CBD did not. CBG also produced the broadest changes in receptor expression.

That does not prove that a CBG cream will protect human skin. It does suggest a better direction for product research. Instead of adding cannabinoids to cosmetics as interchangeable marketing ingredients, developers could select them according to measurable effects on specific pathways, then optimize delivery and dosage for those targets.

The study ultimately shows both the promise and the limits of cannabinoid skin science. CBD and CBG did not erase UVA-induced damage, but they altered how melanocytes managed oxidative pressure, inflammatory messengers, membrane lipids, and receptor signalling. CBG was particularly notable, not because it solved every problem, but because it produced a stronger antioxidant response than the cannabinoid that currently dominates the market.

That is a credible foundation for further research. It is not yet a reason to replace sunscreen with cannabinoids.

References:

¹ Biernacki, M., Sękowski, S., Dobrzyńska, I., Olchowik-Grabarek, E., Jarocka-Karpowicz, I., & Skrzydlewska, E. (2026). Phytocannabinoids regulate lipid metabolism in UVA-irradiated melanocytes. European Journal of Pharmacology, Article 179345. https://doi.org/10.1016/j.ejphar.2026.179345