Sauna marketing loves big claims — detox, cure-alls, miracle wellness. Strip those away and there is still a genuinely interesting body of peer-reviewed research on sauna use, most of it from Finland, where regular sauna bathing has been part of daily life for centuries. Here is what the actual studies say, and what they don't.
The Finnish Cohort Study Everyone Cites
The most-quoted paper on sauna benefits is Laukkanen et al., published in JAMA Internal Medicine in 2015. Researchers followed 2,315 middle-aged men from Eastern Finland for an average of 20 years as part of the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study. Men who used a sauna 4–7 times a week had a markedly lower risk of fatal cardiovascular disease, sudden cardiac death and all-cause mortality than men who used one once a week.
It's an association, not proof of cause and effect — frequent sauna-goers in the study were also generally more active and had healthier cardiovascular risk profiles to begin with, and the researchers were careful to say so. A follow-up review by Laukkanen and Kunutsor in Mayo Clinic Proceedings (2018) pulled together further evidence pointing the same direction, but the same caveat applies: correlation across a population is not the same as a guarantee for any one individual.
Is Sauna Good for a Cold?
This is one of the most-searched sauna questions, and there is an actual trial behind it. Ernst and colleagues ran a small controlled study, published in Annals of Medicine in 1990: 25 volunteers took regular sauna baths, 25 did not, and both groups were tracked for six months. The sauna group recorded significantly fewer colds overall (33 vs 46 episodes) and fewer days with symptoms (221 vs 343) than the control group.
It's a genuinely old, genuinely small study — 50 participants is not a modern-sized trial — and it hasn't been meaningfully repeated at scale since. Treat it as suggestive, not settled science. It's also the reason "does sauna help a cold" keeps circulating as sauna folk wisdom with at least some data behind it, rather than pure myth.
What the Evidence Doesn't Say
None of this research supports "detoxing" through sweat — the amount of anything harmful you sweat out is negligible, and your liver and kidneys do that job. The honest summary of the Finnish data is narrower and still useful: regular heat exposure is associated with better long-term cardiovascular outcomes and, in one small trial, fewer colds. If you have a heart condition, are pregnant, or are on medication that affects blood pressure, talk to your GP before starting regular sauna sessions — especially at the higher frequencies studied in the KIHD cohort.
Making Regular Use Realistic in a UK Garden
The benefit in the Finnish data scaled with frequency — the biggest difference was between once a week and four-plus times a week. That's only realistic if the sauna is a short walk from the back door, heats up quickly, and doesn't feel like an event every time you use it. A sauna at the bottom of the garden that takes an hour of driving to reach gets used twice a year; one a few steps from the kitchen gets used on a Tuesday evening.
That's the practical argument for starting compact rather than waiting for the ultimate garden build. The R-UKU 130 (from £2,190) is a small footprint outdoor cabin sauna for 2–4 people — an easy first step that still heats fast enough for regular use. For solo or two-person sessions, the R-SONIA 130 (from £2,990) is a compact thermo pine cabin that runs comfortably off a standard single-phase supply, which matters if daily convenience — not just square footage — is the point.
If you're still deciding on shape and size, our guides on barrel vs cube saunas and wood-fired vs electric heaters cover the trade-offs, and our 2026 buyer's guide walks through planning, siting and running costs.
Browse the full range at saunado.eu/collections/all, or email sales@saunado.eu for advice on sizing a sauna to how often you'll realistically use it.