Supplements for Skin Health: Science, Marketing or Modern-Day Snake Oil?

There has never been a greater choice of supplements marketed specifically for our appearance. Collagen powders, beauty gummies, antioxidant complexes, multivitamins, “cellular health” formulas and so-called anti-ageing supplements are now a major part of the beauty and wellness industry. They are often promoted with sophisticated language and impressive promises: brighter skin, increased collagen production, cellular regeneration, improved elasticity and even “rejuvenation from within”.

But how much of this is actually supported by science?

At Hazel Clinic in Blackrock, Dublin, we believe this is a question patients should feel comfortable asking. Supplements can have a legitimate and important role in healthcare, particularly when there is a nutritional deficiency or a specific medical indication. However, there is an important difference between correcting a genuine nutritional problem and suggesting that taking additional vitamins, minerals or collagen will somehow reverse the natural ageing process. The latter is a much stronger claim, and one that requires considerably stronger evidence.

Our approach is therefore simple: before recommending or purchasing a supplement, we should ask what problem it is intended to solve, what evidence supports its use, what benefit can realistically be expected and whether the cost is justified by that benefit.

The growing promise of “rejuvenation from within”

The idea that we can improve our appearance simply by taking the right supplement is understandably appealing. It offers an easy solution to something much more complicated. Rather than addressing sun exposure, lifestyle, skincare, medical conditions or the biological processes associated with ageing, we are offered the possibility of taking a capsule or powder that supposedly works at a deeper “cellular” level.

The problem is that skin ageing is not caused by one single process that can be switched off or reversed. It is influenced by genetics, cumulative ultraviolet exposure, changes in collagen and elastin, pigmentation, hormonal changes, inflammation, lifestyle factors and the natural structural changes that occur in the skin and underlying tissues over time. There is therefore no single vitamin, supplement or nutritional formula that can realistically address all of these mechanisms.

This does not mean nutrition is unimportant. Quite the opposite. The skin is an organ and, like every other part of the body, it depends on adequate nutrition to function normally. The important distinction is between providing the nutrients the body needs and assuming that consuming more of those nutrients will automatically make the skin younger.

Vitamins are essential, but more is not necessarily better

Vitamins and minerals are fundamental to normal human physiology. Nutrients such as vitamin C, vitamin D, vitamin B12, folate, iron and zinc all have important functions within the body, including processes that are relevant to healthy skin, hair and nails.

When a patient has a genuine deficiency, correcting it can be extremely important. A person with iron deficiency, for example, may require supplementation as part of appropriate medical management. Similarly, vitamin B12 or vitamin D supplementation may be indicated in patients who are deficient or have a particular nutritional requirement.

However, correcting a deficiency is very different from taking additional amounts of a nutrient in the hope of achieving an aesthetic effect. If the body already has an adequate supply of a particular nutrient, there is no simple principle that says increasing the dose will make the skin healthier or younger. Some vitamins and minerals can also cause adverse effects when taken in excessive quantities.

This is why supplementation should ideally have a clear purpose. Rather than asking which multivitamin is “best for anti-ageing”, a more useful medical question is: is there a nutritional need that we are actually trying to address?

Why the “more is better” approach can be misleading

The modern supplement market often encourages accumulation. A patient might take a multivitamin in the morning, a separate hair supplement, a collagen powder, vitamin D, an antioxidant complex and perhaps a “beauty” drink containing many of the same nutrients.

The individual products may each sound reasonable. The problem is that the combined approach can create a considerable amount of unnecessary supplementation, while making it difficult for the patient to understand what is actually providing a benefit.

This is particularly relevant when supplements are promoted as part of a sophisticated “wellness” routine. A long list of ingredients can create the impression that a product is more advanced or more effective. In reality, the number of ingredients in a supplement tells us very little about whether the product produces a meaningful clinical outcome.

Complexity should not be confused with efficacy.

Collagen supplements: what does the evidence actually show?

Collagen is perhaps the best-known example of the gap that can sometimes exist between marketing and scientific evidence. Oral collagen supplements are widely promoted for improving skin firmness, elasticity and hydration, and there are clinical studies suggesting that they may have some effect on these parameters.

A 2023 systematic review and meta-analysis of randomised controlled trials reported improvements in skin hydration and elasticity following oral collagen supplementation. These findings are relevant and should not simply be dismissed. However, they do not mean that collagen supplements have been proven to reverse skin ageing or produce dramatic rejuvenation.

More recent research has made the picture considerably more nuanced. A 2025 meta-analysis examining 23 randomised controlled trials involving 1,474 participants reported that the apparent benefits became much less convincing when the researchers considered study quality and source of funding. In particular, the positive effects were not observed in the higher-quality studies or in studies that were not industry funded.

This does not allow us to conclude that collagen supplements are completely ineffective. That would be an equally simplistic interpretation of the evidence. What it does tell us is that the evidence is not strong enough to justify presenting oral collagen as a miracle anti-ageing treatment or as an alternative to established dermatological interventions, For patients, that distinction matters.

A small measurable improvement is not the same as dramatic rejuvenation

Another important issue is the way scientific results are communicated to consumers. A study can identify a statistically significant improvement in a particular measurement without that improvement necessarily translating into a dramatic visible change for the patient.

This is particularly important in aesthetic medicine, where patients are understandably interested in what they will actually see in the mirror. A statistically significant change in skin elasticity or hydration is not automatically equivalent to looking ten years younger.

When assessing any supplement, therefore, we should consider not only whether a study found a statistically significant result, but also how large the effect was, how consistently it has been demonstrated, whether it is clinically meaningful and whether the results are reproducible in higher-quality research.

This is one of the reasons why evidence-based medicine is so important. The question is not simply whether something can produce an effect; it is whether the effect is meaningful enough to matter to the patient.

When does the cost become part of the medical question?

The financial side of supplementation is often overlooked. Imagine a supplement costing €80 per month. Over the course of a year, that represents €960. If the product produces a small or uncertain improvement, it is reasonable to ask whether that money could be better invested elsewhere.

For example, depending on the patient’s individual circumstances, a greater benefit might come from appropriate sun protection, evidence-based skincare, investigating a suspected nutritional deficiency, addressing an underlying dermatological condition or having a professional assessment to determine what the skin actually needs.

This is not about assuming that inexpensive products are always better or that supplements are never worthwhile. It is about considering value. A treatment should be judged not only by whether there is some evidence of an effect, but also by the size of that effect, the quality of the evidence, the safety profile, the patient’s individual circumstances and the financial cost.

In medicine, the most expensive option is not automatically the most effective one.

When healthcare becomes a sales pitch

The discussion becomes particularly important when supplements are sold directly to patients by healthcare professionals. There is nothing inherently wrong with recommending a supplement when there is a legitimate clinical or nutritional reason for doing so. The ethical concern arises when the commercial aspect becomes more important than the medical indication.

Patients should be able to ask why a product has been recommended, what evidence supports it, what outcome they should expect, how long they need to take it, whether there are alternatives and what the total cost will be.

We should also be cautious with scientific-sounding language that may give consumers a stronger impression of efficacy than the evidence supports. Terms such as “cellular rejuvenation”, “DNA repair”, “reverse ageing”, “detoxification” or “collagen activation” can sound highly sophisticated, but the presence of scientific terminology does not itself constitute scientific evidence.

The appropriate question is always: what clinical research demonstrates that this particular product produces the claimed result in real people?

The price of a supplement is not evidence of its quality

There is a common assumption that a product sold at a premium price must contain something superior. In reality, price tells us very little about clinical efficacy.

A €120 supplement is not automatically more effective than a €20 supplement. A product sold exclusively through a clinic does not become more scientifically proven because it is being recommended by a healthcare professional. Likewise, a supplement containing twenty different ingredients is not necessarily superior to one containing a single nutrient.

Evidence should stand independently of the price tag, packaging or exclusivity of the product.

This is particularly important in aesthetic medicine, where patients are often investing significant amounts of money in the hope of improving their appearance. They deserve to know whether the expected benefit is genuinely supported by evidence.

The importance of a balanced diet

Before considering supplements for skin health, we should not forget something remarkably simple: food.

A varied and balanced diet provides protein, essential fats, vitamins, minerals, fibre and a wide range of other compounds that contribute to overall health. The body does not operate as a collection of isolated nutrients, and skin health cannot be separated from general health.

This is why questions about diet, sleep, physical activity, smoking, alcohol consumption, sun exposure, medications and medical conditions are often more relevant than immediately deciding which supplement to recommend.

A capsule cannot compensate for a chronically poor diet. Nor can a collagen powder replace adequate protein intake, healthy lifestyle habits or appropriate medical care.

Supplements can complement a healthy diet when they are needed. They should not become a substitute for one.

Skin health does not require an endless list of products

The same principle applies to skincare.

There is a growing tendency to believe that better results require more products: more ingredients, more steps, more active compounds and increasingly sophisticated formulations.

But skin does not necessarily benefit from complexity.

For many people, a well-designed routine based around gentle cleansing, appropriate moisturisation, effective sun protection and evidence-based active ingredients can provide an excellent foundation. If a patient has a specific dermatological condition, the priority should be identifying and treating that condition rather than simply adding another cosmetic product or supplement.

The same philosophy applies to aesthetic medicine. The goal should not be to perform as many treatments as possible. It should be to select the treatment that is appropriate for the patient’s anatomy, concerns and expectations.

Hair supplements deserve the same level of scrutiny

The hair supplement market provides another excellent example. Products containing biotin, zinc, iron, collagen and multiple vitamins are frequently marketed as solutions for hair growth and hair loss.

But hair loss is not a single condition. It can have genetic, hormonal, nutritional, inflammatory, metabolic and other causes. Treating someone with a generic “hair vitamin” without first understanding why they are losing hair may simply delay the appropriate assessment.

In some patients, nutritional deficiencies may be relevant and supplementation can be useful. In others, there may be no nutritional deficiency at all.

The important first step is therefore not necessarily finding the most expensive hair supplement. It is identifying the cause of the problem.

When can supplementation genuinely make sense?

It is important to emphasise that this article is not an argument against supplements.

There are many situations in which supplementation can be appropriate. This may include a documented nutritional deficiency, a specific dietary requirement, a medical condition or circumstances where an individual cannot obtain sufficient nutrients through diet alone.

The decision should be individualised and based on the patient’s medical history, diet, medications, nutritional status and clinical needs.

The key question is simple:

What are we trying to correct or achieve?

If there is a clear answer, supplementation may make sense. If the answer is simply that the product promises to “boost cellular rejuvenation” or “reverse ageing”, then a much more critical assessment of the evidence is warranted.

What does Irish regulation say about supplement claims?

The way supplements are marketed is not simply a matter of opinion. There are regulatory requirements governing food supplements and health claims in Ireland and across the European Union.

The Food Safety Authority of Ireland (FSAI) makes clear that food supplements should not be presented as products capable of preventing, treating or curing disease. Health and nutrition claims are also subject to specific European regulatory requirements.

There is therefore an important distinction between a legitimate nutritional statement and an exaggerated cosmetic promise.

For example, a permitted physiological claim relating to a nutrient’s normal biological function is very different from telling a consumer that taking that nutrient will “rebuild the collagen in your face” or “reverse your wrinkles”.

Marketing should not transform a legitimate nutritional function into a medical promise that the evidence does not support.

Our approach at Hazel Clinic

At Hazel Clinic, our philosophy is straightforward: we would rather give a patient an honest medical answer than sell them a product they do not need.

If a supplement is appropriate, we will explain why. If we believe blood tests or further investigation are necessary, we will recommend them. If there is a dermatological condition that requires treatment, we will focus on the underlying problem. If an aesthetic treatment is appropriate, we will discuss what it can realistically achieve, including its limitations, risks and alternatives.

And if we do not believe a particular supplement will provide meaningful benefit, we should be comfortable saying so.

A medical consultation should not automatically end with a purchase.

Sometimes the most responsible recommendation is simply:

“You don’t need this.”

That is not doing less for the patient. It is part of responsible medical care.

Evidence-based aesthetics means asking better questions

Evidence-based aesthetic medicine does not mean rejecting every new treatment, technology or supplement. Medicine evolves, and new evidence can change what we recommend.

It means asking the right questions before adopting or promoting something.

What is the evidence?

How strong is it?

Was the research conducted independently?

What was actually measured?

How large was the benefit?

Is the improvement clinically meaningful?

What are the risks?

What are the alternatives?

And, importantly, is the expected benefit worth the financial cost to the patient?

These questions should apply equally to skincare products, supplements, injectables, devices and medical treatments.

At Hazel Clinic, we believe patients deserve to understand not only what we recommend, but why we recommend it.

Healthy skin starts with the basics

When it comes to maintaining healthy skin as we age, the most effective strategy is rarely a single miracle product. It is usually a combination of sensible, consistent habits.

A varied and balanced diet provides the nutritional foundation. Regular physical activity and adequate sleep support overall health. Avoiding smoking and excessive alcohol consumption is important. Daily sun protection is essential for reducing cumulative UV-related skin damage. A simple, consistent skincare routine can provide an appropriate foundation for many people.

When there is a genuine dermatological or nutritional problem, professional assessment becomes important. Identifying the cause allows treatment to be targeted rather than relying on a generic product that promises to solve everything.

And when aesthetic treatment is appropriate, it should be approached in exactly the same way: with evidence, realistic expectations and a clear understanding of what the treatment can and cannot achieve.

The bottom line: your skin deserves evidence, not hype

The supplement industry is not inherently bad. Vitamins and minerals are essential, and supplements can be extremely useful when they address a genuine nutritional or medical need.

The problem is the promise of the miracle.

There is a significant difference between supporting normal physiological function and reversing ageing. There is a difference between correcting a deficiency and taking unnecessary high doses. There is a difference between a statistically significant result in a clinical study and a dramatic visible transformation in the mirror.

And there is a difference between medical advice and a sales pitch.

At Hazel Clinic in Blackrock, Dublin, we believe patients deserve honest conversations about all of these distinctions. Our role is not simply to recommend more products or more treatments. It is to understand what the patient actually needs and to recommend an approach that makes medical, scientific and financial sense.

You do not necessarily need the most expensive supplement. You do not necessarily need the most complicated skincare routine. And you certainly do not need to buy something simply because it promises to “rejuvenate your cells”.

Sometimes the best intervention is the simplest one.

Sometimes a supplement is exactly what a patient needs.

And sometimes the most valuable medical advice we can give is:

Save your money, look after the fundamentals, and let’s treat the problem that actually exists.

That, in our view, is what evidence-based dermatology and aesthetic medicine should look like.

Dr Susana Fontana is the Medical Director of Hazel Clinic, a doctor-led dermatology and aesthetic medicine clinic in Blackrock, Dublin. Her approach combines medical assessment, evidence-based dermatology and aesthetic medicine with an emphasis on realistic expectations, patient safety and personalised treatment plans.

This article is intended for general educational purposes and should not replace individual medical advice. Nutritional supplementation should be considered in the context of an individual’s medical history, diet, medications and nutritional needs.