Best pillows: six compared, and the research on synthetic versus feather goes the other way

Loft is the whole thing, and it depends on your shoulders

Almost every complaint about a pillow is a loft complaint wearing a disguise. The job of a pillow is to fill the gap between your head and the mattress so your neck stays in line with your spine, and how big that gap is depends on how you sleep and how broad you are.

Side sleepers need the most, because the gap is the width of your shoulder. Broad shoulders need more again, and this is where cheap soft pillows fail. Back sleepers need medium, enough to support the curve of the neck without pushing the chin towards the chest. Front sleepers need almost nothing, and ideally a pillow you can strip back to almost flat, because anything lofty twists the neck all night.

Combination sleepers are the awkward case, and it is why the heavily contoured memory foam pillows get complaints about being restrictive. If you turn over three times a night you want something that lets you, not something moulded to one position.

The dust mite evidence, which goes the opposite way to the usual advice

Everybody has been told that feather pillows are bad for allergies and synthetic ones are the safe choice. The published measurements say the reverse, and it is worth setting out properly.

A 1999 study put paired new synthetic and feather pillows on twelve beds for twelve months and then measured the main house dust mite allergen on both. The synthetic pillows carried roughly three times as much as the feather ones.

A 2004 study found the mechanism. Electron microscopy measured the pore size of standard synthetic pillow casings at around 57 micrometres, against around 18 micrometres for feather casings. Mites crossed every standard synthetic casing within 24 hours but had not crossed the feather casings after 48. Dust penetration was 0.88 per cent through synthetic against 0.07 per cent through feather. The reason is not the fill, it is the fabric: down cannot be contained by an ordinary weave, so feather pillows have always used a tight cambric casing, and that same tight weave keeps mites and dust out.

A 2006 study found the same direction for fungi, with more species in synthetic pillows than feather ones.

None of this means a feather pillow is right for you if you are allergic to feathers, which is a separate and real thing. And it does not overturn the biggest finding of all, which is that washing works. If dust mite allergy is your actual problem, the ranked order of usefulness is: wash the pillow regularly and hot, use a tightly woven encasement, keep bedroom humidity under about 50 per cent, and only then worry about what the fill is made of.

Fire regulations, and what they mean for a pillow

This one is genuinely surprising, so here is what the Furniture and Furnishings (Fire) (Safety) Regulations 1988 actually do. Pillows are included in the definition of furniture. But they are then expressly excluded from the cigarette resistance test and from the cover match test, and a pillow carries no fire safety label at all, which is why you have never seen one.

What survives is the filling test, and this is where the fills separate. A polyurethane foam filling in slab or cushion form has to pass the wood crib ignition test, which is the most demanding filling test in the regulation, and there is no pillow escape route from it. Untreated commodity foam does not pass it. Feather, down, wool and hollowfibre take a much milder route and pass on their own merits by charring rather than sustaining flame. Latex gets its own separate and gentler test.

The practical consequence: a memory foam pillow legally sold in the UK almost certainly contains flame retardant chemistry somewhere in the foam, and nothing on the label will tell you what. A wool, down or hollowfibre pillow does not need any, and manufacturers of those do not add it. That is the single clearest material difference on this page and almost nobody writes about it.

What CertiPUR and OEKO-TEX actually cover

CertiPUR applies to the polyurethane foam. It sets a ceiling on total volatile organic compound emissions and prohibits certain flame retardants, heavy metals, formaldehyde and phthalates. It is real and it is independently tested. It does not mean zero emissions, it means emissions below a threshold, and it is not a government scheme.

OEKO-TEX Standard 100 applies to textiles. It tests against a long list of restricted substances and requires compliance with the relevant chemical regulations. Class 1 is the infant class and the strictest. What it does not automatically do is certify a foam core inside a certified cover, so if a foam pillow claims OEKO-TEX, it is worth knowing which components the certificate actually covers.

Neither one means chemical free, and any brand implying otherwise is overselling a real certificate.

Antibacterial and antimicrobial claims, and how to test them

A lot of pillows are sold as naturally antibacterial, usually on the basis of bamboo. Bamboo viscose is regenerated cellulose, chemically the same as any other viscose, and the antibacterial performance of the raw plant does not survive that process in any well evidenced way. The American regulator has acted more than once against sellers making unsubstantiated bamboo antibacterial claims.

Here is the useful bit. If a genuine biocide had been added to a product, the Biocidal Products Regulation requires the item to be labelled with the active substance and the biocidal property claimed, and entitles any buyer to written detail free of charge within 45 days of asking. So if a brand claims antibacterial performance, email and ask which active substance is present. Either you get an answer, in which case you know what is in your pillow, or you do not, in which case the claim is about the plant it started as rather than the product you bought.

How often to replace one, and how to test yours

The honest answer is that it varies enormously by fill and nobody should give you one number. Hollowfibre and microfibre polyester are the shortest lived, commonly two years and often less. Memory foam and latex go considerably longer, with latex the most durable fill here. Down lasts well if you plump it, and wool lasts longest of all provided it is fluffed and occasionally redistributed.

The test that works for a fibre or down pillow: fold it in half, and if it stays folded rather than springing back, it is finished. For a foam or latex pillow, look for a permanent dent where your head goes that does not recover during the day.

And before you replace it, consider washing it, if the label allows. A large part of what makes an old pillow feel dead is accumulated body oil and skin scale rather than the fill failing.

Encasements do more than the pillow choice does

If allergy is the reason you are here, a tightly woven pillow encasement is a cheaper and better lever than upgrading the pillow. It puts a barrier with a small enough pore size between you and whatever is in the fill, it can be washed hot far more easily than the pillow itself, and it works regardless of which pillow is inside it. Look for a stated pore size or an allergy certification rather than the word hypoallergenic, which means nothing in particular.