Beyond the Surface: A Functional Medicine Approach to Acne

The limitations of treating acne in isolation

Acne is often managed as a purely surface problem, with treatment focused on topical retinoids, benzoyl peroxide and oral antibiotics. These have a genuine, evidence-based place and help a great many people. But they don’t always address why the skin is inflamed in the first place — which is one reason some patients cycle through flares, clearance and relapse for years. For persistent or scarring acne, systemic options such as isotretinoin can be highly effective and are an important tool; they are also a significant medical decision, with monitoring and side-effects that a patient weighs up with their dermatologist.

A functional-medicine approach doesn’t reject any of this. It asks a complementary question: acne is inflammation of the pilosebaceous unit driven by genetic, hormonal, metabolic and microbial factors — so which of those levers can we influence alongside conventional care?

Why acne is partly a whole-body signal

The single most useful mechanistic idea in modern acne research is the insulin/IGF-1 axis. Foods with a high glycaemic load raise blood glucose and insulin, which in turn raises insulin-like growth factor 1 (IGF-1). IGF-1 does two things that matter for skin: it stimulates the sebaceous glands to produce more oil (sebaceous lipogenesis), and it amplifies androgen signalling. More sebum plus more androgen drive is a recipe for clogged, inflamed follicles. According to PubMed, this IGF-1 pathway is repeatedly identified as a shared mechanism linking diet, hormones and the microbiome to acne (Sánchez-Pellicer et al., 2022, Microorganisms, DOI).

This is why “diet doesn’t affect acne” — an old dermatology reflex — has quietly been revised. It’s not about greasy food causing greasy skin; it’s about what certain foods do to insulin and IGF-1.

The root-cause methodology

An integrative workup looks at the body as an interconnected system. The main areas of focus, with an honest evidence grade for each:

• Diet & nutrition — reducing high-glycaemic-load foods and reviewing dairy. Evidence: reasonably well supported.
• Gut health — considering dysbiosis or conditions such as SIBO. Evidence: biologically plausible, less extensively trialled than in rosacea.
• Hormonal balance — assessing androgen-driven patterns, guided by testing where appropriate. Evidence: androgens’ role is well established; specific supplement protocols vary in quality.
• Micronutrients — correcting deficiencies (notably zinc and omega-3) that influence inflammation. Evidence: growing, with some good trial data.
• Microbiome recovery — supporting gut and skin microbiomes, especially after antibiotics. Evidence: active, rapidly developing research area.

What the research actually shows — diet

According to PubMed, diet is the best-evidenced part of the functional approach. A 2021 review in the American Journal of Clinical Dermatology found that people following low-glycaemic-load diets had measurably fewer acne lesions than those on high-glycaemic-load diets, and identified whey protein’s insulinotropic effect — not dairy fat — as the more likely driver behind the dairy–acne association (Baldwin & Tan, 2021). An earlier systematic review in the British Journal of Dermatology reached a similar but more cautious conclusion: a low-GI diet reduced acne severity in a small randomised trial, while the dairy link “requires closer scrutiny” rather than being settled (Bhate & Williams, 2013).

The newest angle is omega-3. According to PubMed, a 2024 prospective study found that 98% of acne patients were deficient in EPA/DHA at baseline; a Mediterranean diet plus algae-derived omega-3 supplementation raised their omega-3 index and produced significant improvement in both inflammatory and non-inflammatory lesions — plausibly by lowering pro-inflammatory signalling and IGF-1 (Guertler et al., 2024, Journal of Cosmetic Dermatology, DOI). It’s a single study, not proof, but it fits the mechanism neatly.

What the research actually shows — the microbiome

The understanding of acne bacteria has undergone a genuine paradigm shift. According to PubMed, it is not simply that Cutibacterium acnes “overgrows.” Rather, it’s the loss of balance between different C. acnes strains (phylotypes), together with wider skin dysbiosis, that triggers the innate immune system and drives inflammation — with a more virulent phylotype tending to predominate in acne-prone skin (Dréno et al., 2020, American Journal of Clinical Dermatology, DOI). This reframes the goal: not to scorch all bacteria, but to restore a healthy microbial balance — which is also why broad, prolonged antibiotics can be counterproductive, as they flatten that diversity.

The gut–skin axis extends this. A 2022 narrative review describes bidirectional communication between gut and skin microbiota via the immune system, and reports early but positive clinical-trial signals for oral probiotics as an adjunct — again with IGF-1 modulation as one proposed mechanism (Sánchez-Pellicer et al., 2022, DOI). The trials are still small, but the direction is consistent.

An evidence-backed adjunct: zinc

Zinc is one of the few “natural” acne adjuncts with solid trial support. According to PubMed, a systematic review and meta-analysis found that acne patients have significantly lower serum zinc than controls, and that zinc supplementation significantly reduced inflammatory papule counts — as monotherapy or alongside standard treatment — without increasing side-effects (Yee et al., 2020, Dermatologic Therapy, DOI). A broader review of zinc in dermatology attributes this to its antioxidant and immunomodulatory properties, while noting that larger randomised trials are still needed before recommending it as a stand-alone therapy (Searle et al., 2022, Journal of Dermatological Treatment, DOI). It’s a good example of a low-risk, plausibly useful adjunct — not a replacement for proven treatment.

Hormonal factors

Androgens’ role in driving sebum production and acne severity is well established, which is why hormonally-driven patterns (jawline breakouts, premenstrual flares) often respond to approaches that address that axis. In integrative practice, herbal 5-alpha-reductase inhibitors such as saw palmetto are sometimes used on the theoretical basis that they lower DHT — the same rationale as their use in androgenic hair loss. Robust clinical-trial evidence for saw palmetto in acne specifically is limited, so it belongs in the “reasonable, low-risk adjunct with a plausible mechanism” category, not on the same evidence footing as hormonal contraception or isotretinoin.

What a functional workup involves — and its limits

In practice this can include a dietary and lifestyle history, review of any recent antibiotic use, and — where clinically justified — testing for micronutrient status or hormonal patterns. Two honest caveats: some tests marketed in this space (certain gut and hormone panels) have variable validation and should inform a conversation rather than dictate a protocol; and none of this replaces dermatological assessment for moderate-to-severe or scarring acne, where timely conventional treatment prevents permanent marks. The aim is to make conventional treatment work better and relapse less — not to delay it.

Realistic expectations

Addressing diet, micronutrients, gut health and hormonal balance together can meaningfully reduce flare frequency and severity, and some people improve enough to avoid escalating to systemic medication. Patients often notice benefits beyond the skin — energy, digestion, mood — which is consistent with treating acne as a systemic, not purely cosmetic, condition. Equally, results are gradual (think months, not days), individual, and best tracked objectively rather than by a single good or bad week.

How we approach it

Our view is simple: use what the evidence supports, be candid about what’s still emerging, and combine root-cause work with — never instead of — good dermatological care. If you’d like to understand which of these levers is most relevant to your skin, that’s exactly what a consultation is for.

References

According to PubMed, the sources cited above include:

• Baldwin H, Tan J. Effects of Diet on Acne and Its Response to Treatment. Am J Clin Dermatol. 2021;22(1):55–65.
• Bhate K, Williams HC. Epidemiology of acne vulgaris. Br J Dermatol. 2013;168(3):474–485.
• Dréno B, Dagnelie MA, Khammari A, Corvec S. The Skin Microbiome: A New Actor in Inflammatory Acne. Am J Clin Dermatol. 2020;21(Suppl 1):18–24. DOI
• Sánchez-Pellicer P, et al. Acne, Microbiome, and Probiotics: The Gut–Skin Axis. Microorganisms. 2022;10(7):1303. DOI
• Guertler A, et al. Exploring the potential of omega-3 fatty acids in acne patients: A prospective intervention study. J Cosmet Dermatol. 2024;23(10):3295–3304. DOI
• Yee BE, Richards P, Sui JY, Marsch AF. Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis. Dermatol Ther. 2020;33(6):e14252. DOI
• Searle T, Ali FR, Al-Niaimi F. Zinc in dermatology. J Dermatolog Treat. 2022;33(5):2455–2458. DOI

General educational content only; not medical advice. A functional approach to acne is intended to complement, not replace, assessment and treatment by a qualified dermatologist or doctor. Any supplement or dietary change should be discussed with your practitioner, particularly if you take other medication.