Last night, we hosted an event and covered a lot. Questions about collagen. The gut. Vitamin D. LED masks. Hair loss.
Here’s your evidence-led recap — clear, honest, and rooted in what actually works.
Because at No. 23 Skin, we don’t chase trends. We follow data. And we help you look after your skin so you can get on with living in it. Thanks to Dr Sukhi Dhariwal and Dr Cherry Armstrong for discussing important topics in skin health.
The short answer: yes — but it’s nuanced.
Your gut contains trillions of microorganisms (the gut microbiome). Beneficial bacteria — probiotics — help regulate immunity and inflammation. They thrive on fibre-rich foods (prebiotics): vegetables, fruit, beans and pulses, and wholegrains.
Research shows that disruption of the gut microbiome (dysbiosis) is associated with inflammatory skin conditions including acne, eczema and psoriasis.
A 2018 review in Frontiers in Microbiology highlighted immune and inflammatory pathways linking gut imbalance with acne and psoriasis.¹
A 2020 systematic review in Dermatology and Therapy reported growing evidence for microbiome involvement in acne pathogenesis.²
Important: gut imbalance is rarely the sole cause of skin disease. But it can worsen inflammation.
So what’s sensible?
Eat fibre.
Reduce ultra-processed foods.
Support overall metabolic health.
Don’t expect one probiotic capsule to “fix” chronic acne.
As with everything in wellbeing…. It’s a systems approach. Not a silver bullet.
Your skin also has its own ecosystem of bacteria, fungi and viruses. When balanced, it protects you. When disrupted, inflammation increases.
This is why we don’t recommend harsh stripping cleansers. Over-exfoliating doesn’t make skin healthier. It destabilises it.
Evidence in this area is still evolving, but dermatology increasingly recognises the importance of maintaining barrier integrity and microbiome balance through:
Gentle, low-pH cleansers
Ceramide-rich moisturisers
Avoiding overuse of actives
Simple works.
Collagen is the structural protein holding skin, bone, ligaments and muscle together. UV radiation, smoking, age, and oxidative stress degrade collagen fibres over time.
SPF50+ daily remains the single most powerful collagen-preserving intervention. Nothing competes with it.
Evidence is mixed but emerging.
A 2021 systematic review in International Journal of Dermatology found oral hydrolysed collagen may improve skin elasticity and hydration after 8–12 weeks.³
However, many studies are small and industry-funded.
Our view:
If you want to try it, document properly. Baseline photo. Repeat at 12 weeks. Assess objectively.
Collagen creams? No. The molecules are too large to penetrate the epidermis. They moisturise at best.
In the UK, deficiency is common.
Vitamin D supports immune regulation and skin barrier function. In melanoma patients, observational studies have shown that adequate vitamin D levels are associated with improved survival outcomes.⁴ Our dermatologists will prescribe Vitamin D to melanoma patients to improve outcomes should recurrence occur.
General adult dosing in the UK:
400–1000 IU daily (maintenance)
Higher doses only under medical supervision
If you have a history of skin cancer or immune-mediated disease, this should be individualised with your doctor.
Evidence is strong for B3.
A landmark Phase III randomised controlled trial (ONTRAC study) published in New England Journal of Medicine (2015) showed that 500mg oral nicotinamide twice daily reduced new non-melanoma skin cancers (SCCs and BCCs) by 23% in high-risk patients.⁵
Topical niacinamide also:
Improves barrier function
Reduces inflammation
Helps regulate oil production
Supports pigmentation control
It’s one of the most useful ingredients in some moisturisers too.
Important caveat:
Other B vitamins are not equal. High-dose B12 has been associated with acne flares in some individuals.
Personalisation matters.
Biotin is heavily marketed for hair growth.
Evidence supports its use in brittle nail syndrome.⁶
Evidence for hair growth in individuals without deficiency? Very limited.
If you’re experiencing hair thinning, diagnosis comes first:
Female pattern hair loss
Telogen effluvium
Autoimmune conditions (scarring alopecia)
Hormonal shifts
Treating without diagnosis wastes time. A dermatologist can assess and prescribe evidence-based treatments, such as minoxidil when appropriate.
Retinoids remain one of the most evidence-backed topical interventions in dermatology.
They:
Increase epidermal turnover (i.e. more new skin cells, more quickly)
Stimulate collagen synthesis
Improve pigmentation
Reduce fine lines
Prescription-strength retinoids work faster and have the best evidence for anti-ageing (if you’re a patient of ours we can help with this, if not, then get in touch and we can give you the steps to building up to prescription retinols for your skin specifically). Over-the-counter retinols can be effective but require patience.
Start 1–2 times weekly at night (as it makes you photosensitive). Build slowly. Protect with SPF.
Consistency beats intensity.
Hyaluronic acid (low molecular weight forms), ceramides and simple moisturisers improve barrier function and reduce transepidermal water loss. Remember to stay hydrated on the inside by drinking water too.
Apply moisturiser within minutes of bathing to lock hydration in. If you have dry skin, check out this blog post for some recommendations.
You do not need a £200 cream.
Barrier health is not glamorous. But it works.
Broad-spectrum SPF50+ daily. UVA and UVB protection. Use a specific SPF product — not just what’s in your tinted moisturiser as you tend to apply less and it may not have the required level of protection.
SPF is your collagen insurance policy. Your pigmentation prevention plan. Your skin cancer risk reducer.
We will never tell you to avoid the beach.
We will tell you to reapply.
UV rays and skin ageing – this is quite a famous picture of a truck driver who had one side of his face exposed to UV rays and one side shaded.
Photo credit: (New England Journal of Medicine) The jarring effects of UV radiation.
Yes — with caveats.
Studies show improvements in collagen density and skin texture after repeated treatments.
Demonstrated reduction in inflammatory acne lesions when used regularly over 7 weeks.
Most strong evidence comes from in-clinic, medical-grade devices (such as Dermalux). At-home masks can help mild acne if used consistently (4–7 times weekly), but power output is lower.
Consistency is key. Brand quality matters. If you’re prepared to invest, we recommend:
SPF50+ daily
Retinoids – prescription are stronger, but some over the counter ones will work in the beginning.
Niacinamide – supplement of Vitamin B3 and topically.
Barrier repair – hydration with ceramides
Evidence-based treatments
Personalised plans
Skin is your largest organ. It adapts with you. It reflects your health. It deserves support — not obsession.
We’re not here to tell you to stop living.
We’re here to protect your skin so you can.
If you have a specific medical concern book to see one of our dermatologists for help
If you are due your skin cancer check, book for a mole check online.
or want clarity on what actually suits your skin and to discuss treatments that will support faster results — book in for a complimentary consultation by emailing us here. We’ll make it simple.
Do share this with anyone you know who is interested in their skin and overall skincare – simple actions really can make a difference.
If you were at the event — thank you for coming.
And if you’re reading this online — welcome.
Helen & Dr Cherry
hello@23skin.co.uk
02039411815
23 Ansdell Street, London W8 5BN
Salem I et al. Front Microbiol. 2018;9:1459.
Lee SY et al. Dermatol Ther. 2020;10(5):1045–1058.
de Miranda RB et al. Int J Dermatol. 2021;60(12):1449–1461.
Newton-Bishop JA et al. J Clin Oncol. 2009;27(32):5439–5444.
Chen AC et al. N Engl J Med. 2015;373:1618–1626.
Colombo VE et al. J Am Acad Dermatol. 1990;23(6 Pt 1):1127–1132.
Avci P et al. Semin Cutan Med Surg. 2013;32(1):41–52.
Papageorgiou P et al. Br J Dermatol. 2000;142(5):973–978.
Follow us
no23skin