Can Calendula Really Heal Skin? What the Science Actually Says

Calendula has been rubbed onto damaged and irritated skin for centuries. Modern science has discovered several reasons why that tradition might make biological sense. But does calendula actually heal wounds, or has skincare marketing taken an intriguing botanical and made the evidence sound stronger than it really is?

There is perhaps no word more closely associated with calendula than healing. Search for calendula skincare and the descriptions are remarkably consistent: healing balm, healing salve, skin repair cream, wound healing botanical. For generations, preparations made from the brilliant orange flowers of Calendula officinalis have been applied to irritated, grazed and damaged skin, and it is tempting to assume that the question has already been settled. Calendula heals skin.

Except science requires us to ask a slightly different question. What do we actually mean by healing, and when researchers investigate calendula under controlled conditions, how much of its traditional reputation survives? The answer, as we set out in more biological detail in the Calendula monograph, turns out to be considerably more interesting than either it works or it does not.

First, skin does not simply heal

When we look at a small cut gradually disappear, healing appears almost effortless. Underneath the surface, something extraordinary is happening. Wound repair is not a single biological event. It is a highly coordinated sequence involving blood vessels, platelets, immune cells, fibroblasts, keratinocytes, extracellular matrix and signalling molecules, much of it building back the same barrier structures described in The Skin Barrier.

Scientists generally describe several overlapping phases. Immediately following injury, the body must control bleeding: blood vessels constrict and platelets aggregate, forming a clot that also provides a temporary matrix across which repair cells can migrate. Inflammation follows, as immune cells move into the damaged tissue to remove microorganisms, damaged cells and debris. Despite the way the word is sometimes used in skincare marketing, inflammation is not inherently bad. Without an appropriate inflammatory response, wounds would not heal normally, and the problem arises only when inflammation is excessive, inadequate or persists for too long.

The wound then begins rebuilding during a proliferative phase: fibroblasts produce extracellular matrix, new blood vessels develop, granulation tissue fills the wound, and keratinocytes migrate across the surface in a process called re-epithelialisation, gradually restoring the protective epidermal covering. Even after a wound appears closed, repair continues through remodelling, as collagen and other structural components are reorganised over weeks and months. Healing is therefore not something one ingredient simply switches on. It is a biological programme involving multiple interacting systems, and that distinction matters when assessing calendula.

Why did calendula become associated with healing?

The reputation is much older than modern cosmetic marketing. Calendula officinalis, commonly known as pot marigold, has a long history within European herbal practice, and its flowers were prepared as infusions, tinctures, ointments and oil macerates applied traditionally to minor wounds and inflamed skin.

That history has not entirely disappeared from contemporary medicine. The European Medicines Agency’s Committee on Herbal Medicinal Products recognises calendula flower preparations as traditional herbal medicinal products for the symptomatic treatment of minor skin inflammation, such as sunburn, and as an aid in the healing of minor wounds. That sounds impressive, but one phrase matters enormously: traditional use. Within European herbal regulation, this does not mean an ingredient has been demonstrated through high quality clinical trials to be an effective wound treatment. It means that its long history of use, together with available evidence and an acceptable safety profile, makes the traditional application plausible. The HMPC monograph explicitly notes that there is insufficient evidence from clinical trials to establish calendula’s effectiveness as a well established medicinal use, a distinction that can quietly disappear when scientific language reaches skincare marketing. “Traditionally used as an aid in healing minor wounds” gradually becomes “scientifically proven to heal skin”. Those statements are not equivalent.

So why are scientists interested?

Because calendula is chemically far from inactive. Its flowers contain a diverse mixture of plant metabolites, including triterpenoids and triterpene esters, flavonoids, carotenoids, phenolic compounds, sterols, polysaccharides and smaller quantities of volatile compounds. Different calendula preparations extract different proportions of these substances, which immediately creates one of the challenges in interpreting research: a calendula oil macerate is not chemically identical to an alcoholic extract, an aqueous preparation is not equivalent to either, and a finished ointment may behave differently again depending upon its concentration, extraction method and formulation. When a clinical trial reports an effect from a particular calendula preparation, we cannot automatically assume that every cosmetic containing the word calendula on its ingredient list will produce the same effect.

One of the most biologically plausible areas of calendula research concerns inflammation. Experimental research suggests that several calendula constituents, particularly triterpenoid compounds related to faradiol, can influence pathways involved in inflammatory signalling, and a classic study isolating faradiol esters from calendula flowers found their anti-oedematous activity comparable to indomethacin in an experimental model. That provides a plausible mechanism for some of calendula’s traditional association with uncomfortable or irritated skin, but demonstrating that a plant extract changes inflammatory signalling in cultured cells or experimental animals is not the same thing as demonstrating that a calendula cream meaningfully improves healing in humans. Mechanistic evidence tells us an effect is biologically plausible. Clinical evidence tells us whether that effect actually matters to patients. We need both.

Granulation tissue: an interesting clue

One of the more intriguing findings from calendula research concerns granulation tissue, the vascular connective tissue that develops within a healing wound and provides part of the structural foundation from which repair proceeds. A systematic review examining calendula extract and wound healing found reasonably consistent evidence from animal studies suggesting faster resolution of the inflammatory phase and increased formation of granulation tissue. That provides a possible biological explanation for observations that may have contributed to calendula’s traditional reputation, but animal evidence is not human evidence. Laboratory animals allow researchers to study wound biology under controlled conditions that would be impossible or unethical in people, and they are invaluable research models, but they are not miniature humans. A botanical that accelerates an aspect of experimental wound healing does not automatically become an effective clinical wound treatment.

What happens when calendula is tested in people?

This is where the story becomes much less tidy. A 2019 systematic review examined 14 studies investigating Calendula officinalis extract and wound healing, seven animal experiments and seven clinical trials. The authors found evidence suggesting beneficial effects in some areas of wound repair, particularly regarding the inflammatory phase and granulation tissue, but clinical results varied considerably according to the type of wound being studied. Some studies were encouraging, others found little or no benefit, and the researchers ultimately concluded that larger and better designed randomised controlled trials were needed.

An earlier systematic review reached an even more cautious conclusion. After evaluating randomised controlled trials using topical calendula monopreparations, its author identified six trials but considered only one to be of good methodological quality, concluding that the evidence supporting topical calendula for acute and chronic wounds was weak. That does not mean calendula does not work. It means something scientifically quite different: we do not yet have sufficiently strong evidence to say confidently that it does.

The curious case of venous leg ulcers

Some of the most encouraging clinical findings involve venous leg ulcers, chronic wounds associated with impaired venous circulation that can be extraordinarily difficult to heal. In one small clinical study, patients treated with an ointment containing calendula extract experienced a greater reduction in total ulcer surface area over three weeks than those receiving saline dressings. A later clinical investigation reported encouraging results using a defined calendula extract in patients with venous leg ulcers, including a significant increase in healing velocity compared with the control group.

These findings deserve attention, but they do not settle the question. Venous ulcers are medically complex wounds whose management includes assessment of the underlying vascular disease, compression therapy where appropriate, infection management and specialist wound care. Small calendula studies cannot justify replacing those interventions. They instead provide a reason to investigate calendula more rigorously, which is an important difference.

Calendula after childbirth and surgery

Calendula has also been investigated in surgical and obstetric wounds. A randomised trial involving 100 women examined calendula ointment following episiotomy, finding significantly lower pain from the second day onwards among women using calendula compared with standard care, alongside improvements in wound appearance including redness and oedema. A separate randomised controlled trial involving 72 women investigated calendula ointment following caesarean section, assessing wound healing on days three, six and nine using the REEDA scale, and reported that calendula considerably increased the speed of wound healing compared with control.

Again, these are intriguing findings, but relatively small individual studies should not be transformed into universal claims that calendula accelerates surgical wound healing. Replication matters, formulation matters, study design matters, and postoperative wounds require appropriate medical care regardless of whether a complementary topical preparation is being investigated.

Then there is radiation dermatitis

Perhaps no area demonstrates the difficulty of interpreting calendula research better than radiation dermatitis. Radiotherapy can damage healthy skin within the treatment field, producing redness, discomfort and sometimes more significant inflammatory reactions. In 2004, a phase III randomised trial involving 254 people receiving radiotherapy for breast cancer compared calendula ointment with trolamine, and grade 2 or greater acute dermatitis occurred significantly less frequently in the calendula group, alongside fewer radiotherapy interruptions and less radiation associated pain. It looked like powerful evidence for calendula.

But science does not stop after one positive study. A later randomised controlled trial compared calendula with a standard moisturising cream in women undergoing breast radiotherapy and did not detect a significant difference in grade 2 or greater dermatitis between the groups, although the study recruited fewer participants than intended and was therefore underpowered. A broader 2023 systematic review and meta-analysis of natural and miscellaneous agents for the prevention of acute radiation dermatitis examined five natural products, aloe vera, oral enzymes, olive oil, calendula and curcumin, and found that only oral enzymes and olive oil produced a statistically significant reduction in grade 2 or greater dermatitis. Calendula was not among them.

This is an excellent example of how evidence develops. One trial produces an exciting result, another does not reproduce it convincingly, researchers combine the available evidence, and confidence becomes more cautious. That is not science failing. That is science working.

Why one calendula product is not another

There is another problem that rarely appears on cosmetic labels. Calendula is not one standardised substance. Researchers might use dried flower preparations, hydroalcoholic extracts, tinctures, oil macerates or ointments containing defined extracts produced by different methods and at very different concentrations, and even the plant material itself varies according to cultivar, growing conditions, harvest timing, storage and processing. If researchers test a precisely characterised pharmaceutical calendula extract, their results cannot automatically be transferred to a moisturiser containing a small quantity of calendula infused oil. The name of the plant may be identical. The exposure is not.

Does calendula kill bacteria in wounds?

Calendula extracts have demonstrated antimicrobial activity in laboratory studies, which has contributed to claims that calendula can protect wounds against infection. This requires considerable caution. Putting bacteria into direct contact with a concentrated botanical extract in a laboratory is fundamentally different from treating an infected wound, which contains tissue, proteins, immune cells, extracellular fluid and complex microbial communities. An extract that inhibits bacterial growth in a laboratory assay is not automatically a clinically useful antiseptic, and calendula should not be regarded as a replacement for appropriate wound cleaning, antisepsis where indicated, antibiotics when medically necessary or professional assessment of suspected infection.

Can calendula prevent scars?

Scar formation is part of normal wound repair, and its eventual appearance depends upon numerous factors including wound depth, anatomical location, genetics, inflammation, infection, mechanical tension, age, healing time and collagen organisation. Although calendula has been investigated in relation to wound repair, there is currently insufficient high quality clinical evidence to conclude that routine calendula application reliably prevents or significantly reduces scarring. That claim moves considerably further than the evidence allows.

What about ordinary irritated skin?

Here the discussion changes slightly, because a cosmetic product does not have to heal a wound to be useful. This is particularly important because cosmetic value and medicinal efficacy are not the same thing. Calendula’s chemistry and history make it an interesting ingredient for formulations designed around skin comfort and conditioning, and a well formulated calendula product may provide emollience through its carrier oils, support the sensory qualities of a formulation and deliver botanical constituents with plausible anti-inflammatory and antioxidant activity, none of which requires a claim that the product treats wounds.

This may ultimately be where calendula fits most comfortably within modern skincare. Not as a miracle healer, not as an alternative medicine cabinet, but as a well established botanical ingredient whose traditional use has generated genuinely interesting scientific questions.

Natural does not mean risk free

Calendula generally has a favourable safety profile when appropriately formulated, but it belongs to the Asteraceae family, which also contains plants including daisies, chrysanthemums, ragweed and arnica. Individuals sensitised to members of the Asteraceae may need particular caution with calendula preparations. This is another useful reminder that the word natural tells us where an ingredient came from. It tells us remarkably little about whether an individual person will tolerate it.

So, does calendula heal skin?

The scientifically responsible answer is possibly, under some circumstances, with some preparations, but the evidence is not strong enough to support the sweeping claims often made for it.

There are several reasons to take calendula seriously. Its traditional association with minor wounds and inflamed skin is unusually persistent. Its chemistry contains compounds with biologically plausible effects relevant to inflammation and tissue repair. Experimental studies provide encouraging evidence involving the inflammatory phase and granulation tissue, and some human clinical studies have reported improved wound outcomes. But there are equally important reasons for restraint. Clinical studies remain relatively few, some are small, methodological quality varies, calendula preparations differ substantially, results have not always been reproduced, and systematic reviews continue to call for larger, better designed randomised trials.

Perhaps the most accurate description of calendula is therefore not a proven healing botanical. It is a traditional healing botanical with an intriguing scientific case that remains incompletely proven. That distinction may sound less dramatic. We find it considerably more interesting, because somewhere between the medieval salve and the modern randomised controlled trial lies one of the central questions of botanical science: what happens when something people have observed for centuries is finally subjected to scientific scrutiny? Sometimes tradition turns out to be wrong. Sometimes science discovers an explanation. And sometimes, as with calendula, the evidence leaves us somewhere fascinating in between.

Continue exploring

References

• European Medicines Agency, Committee on Herbal Medicinal Products (HMPC). European Union herbal monograph on Calendula officinalis L., flos, revision 1. EMA/HMPC/437450/2017, adopted 27 March 2018. EMA/HMPC monograph
• Zitterl-Eglseer, K. et al. (1997). Anti-oedematous activities of the main triterpendiol esters of marigold (Calendula officinalis L.). Journal of Ethnopharmacology, 57(2), 139-144. doi:10.1016/S0378-8741(97)00061-5
• Givol, O. et al. (2019). A systematic review of Calendula officinalis extract for wound healing. Wound Repair and Regeneration, 27(5), 548-561. doi:10.1111/wrr.12737
• Leach, M.J. (2008). Calendula officinalis and wound healing: a systematic review. Wounds: A Compendium of Clinical Research and Practice, 20(8), 236-243. ResearchGate record
• Duran, V. et al. (2005). Results of the clinical examination of an ointment with marigold (Calendula officinalis) extract in the treatment of venous leg ulcers. International Journal of Tissue Reactions, 27(3), 101-106.
• Buzzi, M., de Freitas, F. & Winter, M. (2016). Therapeutic effectiveness of a Calendula officinalis extract in venous leg ulcer healing. Journal of Wound Care, 25(12), 732-739. doi:10.12968/jowc.2016.25.12.732
• De Angelis, C. et al. (2022). Use of calendula ointment after episiotomy: a randomized clinical trial. Journal of Maternal-Fetal & Neonatal Medicine, 35(10), 1860-1864. doi:10.1080/14767058.2020.1770219
• Jahdi, F. et al. (2018). The impact of calendula ointment on cesarean wound healing: a randomized controlled clinical trial. Journal of Family Medicine and Primary Care, 7(5), 893-897. doi:10.4103/jfmpc.jfmpc_121_17
• Pommier, P. et al. (2004). Phase III randomized trial of Calendula officinalis compared with trolamine for the prevention of acute dermatitis during irradiation for breast cancer. Journal of Clinical Oncology, 22(8), 1447-1453. doi:10.1200/JCO.2004.07.063
• Siddiquee, S. et al. (2021). Efficacy of topical Calendula officinalis on prevalence of radiation-induced dermatitis: a randomised controlled trial. Australasian Journal of Dermatology, 62(1), e35-e40. doi:10.1111/ajd.13434
• Robijns, J. et al. (2023). Natural and miscellaneous agents for the prevention of acute radiation dermatitis: a systematic review and meta-analysis. Supportive Care in Cancer, 31(3), 195. doi:10.1007/s00520-023-07656-z