Best Bamboo Underwear for Women: 7 UK Brands Compared

We make bamboo viscose boxer shorts, so we are one of the seven. We have not run laboratory tests and will not pretend we did. Specifications below were checked against each brand's own product pages in July 2026 and again in October 2026. Where a claim belongs to a brand, we name whose it is. That includes a claim of our own that we have now removed, and we explain why below.

Start here: most of what you have read about bamboo underwear is not true

Before the brands, the thing that will save you money.

Bamboo underwear is genuinely comfortable. Viscose made from bamboo is smooth, breathable and moves moisture faster than cotton. Those are the real reasons to buy it. If sweat is the main reason you are looking, our guide to moisture wicking underwear compares bamboo viscose with synthetics, merino and absorbent pants.

Almost everything else the category tells you is under researched. We checked what seven brands and retailers currently claim, and found: antibacterial, hypoallergenic, "4.5x more breathable than cotton", "releases 35% more oxygen than other trees", "moisture absorption 2 times better than cotton", and "100% natural material".

Unfortunately none of that has been evidenced by research (yet). Viscose made from bamboo is a chemically processed fibre, not raw bamboo. The antibacterial compound sometimes credited to the growing plant does not survive the process that turns bamboo pulp into viscose, so it is not present in any finished bamboo viscose garment. Not ours, not anyone's. That specific claim set has been the subject of regulatory action in the United States.

An earlier version of this article said our own fabric had antibacterial properties. It does not. We have removed it, and we have removed it from our product pages too. We would rather tell you that than quietly edit it out.

So when you compare the seven below, compare them on fabric composition, leg length, size range, certification and price. Ignore the adjectives.

The seven compared

On a phone, swipe the table sideways to see every column.

Specifications and prices checked on each brand's own website, or a UK stockist, between 4 and 7 October 2026. Marks & Spencer could not be rechecked in October, so its row is from 30 July 2026. We have no commercial relationship with any of these brands.

Best bamboo boxers in the UK

Worth separating out, because "bamboo underwear" and "bamboo boxers" are not the same purchase.

Most bamboo underwear brands make briefs, boyshorts and thongs. Very few make an actual long-leg boxer. Of the seven above:

• Flissie makes a 6 inch and 9 inch boxer short. Ours, so weigh it accordingly
• Step One's Body Short has a short leg with friction-resistant inner-leg panels, which is a different approach to the same problem
• Boody's boyleg and BAMBOO COOL's boyshort are short-leg. Comfortable, but they do not reach the point where most thighs touch. Boody also makes 6 and 10 inch Seamfree Undershorts, slip shorts in 79% viscose from bamboo, which we compare with ours in our Boody review
• BAM makes bamboo boxers for men. For women it now sells a Smoothwear Seamless Midi Short as well as briefs, but it does not state a leg length, and sizes stop at UK 18
• Spairs and M&S stock briefs and short styles rather than long-leg boxers

If a long leg is what you are after, that narrows to Flissie (us) and Boody's undershorts, or, at a shorter length with panels, Step One. If you want a long leg and you do not mind that it is not bamboo viscose, the wider field is in our long-leg anti-chafing comparison, where Woxer's modal and Thigh Society's cooling knit both reach 9 inches.

Which to pick, by what you actually want

• A long leg for thigh chafing: Flissie women's bamboo boxer shorts (ours), 6 or 9 inch, Boody's 6 or 10 inch undershort, or Step One's panelled short
• The softest feel with no leg elastic at all: Boody's boyleg replaces the leg band with a soft hem, which matters if elastic marks are your problem
• The lowest price: Spairs at 5 packs from £9.99, or M&S multipacks
• Buying on the high street with easy returns: Marks & Spencer
• A UK brand you can look up: Flissie, BAM, Spairs and M&S are all UK. Step One is stocked at John Lewis
• Multipacks from Amazon: BAMBOO COOL, which sells in 4 and 5 packs and advises sizing down because of the stretch
• Sizes above UK 30: none of these seven. Snag runs UK 4 to 36 and Chaffree covers UK 6 to 34, though neither is bamboo viscose

The seven, one by one

Each card gives the price, who it suits and the trade-offs, checked between 4 and 7 October 2026 unless it says otherwise. Ours is first because we make it; the rest follow the table.

1. Flissie women's bamboo boxer shorts (ours)

2. Boody

3. Step One Body Shorts

4. BAM

5. BAMBOO COOL

6. Spairs

7. Marks & Spencer

What each brand claims, and whose claim it is

Comparison articles usually launder marketing into fact. Here is who says what.

BAMBOO COOL states its fabric is "up to 4.5x more breathable than cotton". That is their figure. We have not seen the test method behind it and would treat it as marketing.

Boody describes its fabric as buttery-soft and seamfree. The seamfree construction is verifiable, it is knitted as a tube. The composition, 79% viscose from bamboo with 15% nylon and 6% elastane, is published, which means roughly a fifth of it is not bamboo at all. They label it accurately, which is more than much of this category manages.

Step One calls its inner-leg panels UltraGlyde and positions them as friction-resistant. Their term, their claim. The composition, 95% viscose made from bamboo and 5% spandex, is published and checkable.

Various retailers in this category state that bamboo is antibacterial or hypoallergenic. It is not, for the reason given above. Be sceptical of any brand that says it.

Us: Flissie women's bamboo boxer shorts are 95% Tanboocel bamboo viscose with 5% elastane, dyed to OEKO-TEX Standard 100, which means tested for harmful substances. That is the extent of what we will claim about the fabric.

The sustainability question, honestly

This is where the category is at its worst, so here is what can and cannot be said.

What is reasonable to say. Bamboo grows fast and regrows from the same root system without replanting. Closed-loop viscose production recovers and reuses most of the solvent and water, which is meaningfully better than open-loop. OEKO-TEX Standard 100 certification means the finished fabric has been tested for harmful substances.

What is not. That bamboo viscose is biodegradable when the garment contains elastane, because it does not fully break down. That it uses a specific percentage less water than cotton, because the figures circulating are uncited and inconsistent. That it is "eco-friendly" as a standalone phrase, because the words mean nothing without a stated basis. That bamboo absorbs a specific percentage more carbon dioxide than trees, which is a claim about the plant, not the fabric on your body.

Our own position. Ours is closed-loop production, OEKO-TEX Standard 100 dyed, and posted in plant-based packaging that is industrially compostable. We previously said our packaging decomposes within three months. That is only true under industrial composting conditions, so we have stopped saying it without that qualification. Viscose from bamboo is a processed fibre, the processing matters, and better processing is not the same as the fabric being green.

If a brand's sustainability page gives you percentages without sources, that tells you something.

What to check before you buy any bamboo underwear

The four things worth two minutes of your time:

1. The actual composition. "Bamboo" on the label usually means viscose made from bamboo, often blended with nylon or elastane. A pair described as bamboo can be 20% something else, which is fine, but you should know
2. The leg measurement, if you are buying for chafing. Most brands do not publish one. Boyleg, boyshort and body short can mean anything from 2 to 5 inches
3. Certification, not adjectives. OEKO-TEX Standard 100 and closed-loop production are checkable. "Eco-friendly" and "natural" are not
4. The wash instructions. Almost all bamboo viscose wants a cool wash and no fabric softener. If you tumble dry your underwear, you will not get the longevity you paid for

Our own pair, and where it loses

Best for: a long leg for thighs that rub, in bamboo viscose.

Flissie women's bamboo boxer shorts come in a 6 inch or 9 inch leg, in bamboo viscose, UK 8 to 30, with every size the same price. £20 a pair, or £13 a pair in a 7 pack. Free UK delivery, 60 day comfort guarantee, free size swap on your whole first order. Designed in Derbyshire.

"Really comfortable, felt cool and not sweaty during the recent hot weather. Will be buying more." Patricia, verified review

"Very lightweight, so far it's making hot and humid days bearable." Lynette, verified review

Where it loses:

• We are not the cheapest. Spairs starts at £9.99 for five pairs. We will never compete with that
• It needs a cool wash and air drying. Tumble dry it and you take the softness out. See the care guide
• Our size range stops at UK 30. Boody and BAMBOO COOL both offer sizes we do not, and outside bamboo entirely, Snag goes to UK 36
• Sizing takes a go. Between sizes, size up. Common enough that the size swap on your whole first order is free

"These are very comfortable and cool to wear. Prevents chafing when wearing dresses. They have been a godsend in this hot weather. They wash well too!" Marlene, United Kingdom, verified review (reviewer earned a reward for a future purchase)

"Fabulous once I got the right size!" marian c., United Kingdom, verified review (reviewer earned a reward for a future purchase)

There are around 350 more of those, and we publish the critical ones too:

"Really nice product. Shame they don't have bras!" G.V., verified review

Our boxer shorts are here, and the size guide has hip and waist measurements.

A note on men's bamboo underwear

We only make women's, so we are the wrong people to ask. BAM and Step One both do men's bamboo ranges and both are easy to buy in the UK. We mention it only because people land here looking, and sending you away is more useful than pretending otherwise.

Your questions answered

What is the best bamboo underwear for women?

Depends on the style. If your thighs rub, Flissie women's bamboo boxer shorts (we make them), with a 6 or 9 inch leg, or Boody's 6 or 10 inch undershort. For the softest short-leg option with no leg elastic, Boody's boyleg. For price, Spairs or M&S multipacks. For anti-chafe panels in a short style, Step One. Compare composition and leg length rather than adjectives.

What are the best bamboo knickers in the UK?

If you want briefs, boyshorts or thongs rather than a long leg, Boody, Spairs and Marks & Spencer are the easiest to buy in the UK, and Spairs is the cheapest at five packs from £9.99. Bamboo knickers and bamboo boxers are different purchases: knickers stop at the hip, so they will not help with thighs rubbing.

What are the best bamboo boxers in the UK?

Very few bamboo brands make a genuine long-leg boxer. Flissie women's bamboo boxer shorts (we make them) come in 6 and 9 inch. Step One's Body Short is shorter with friction-resistant inner-leg panels. Boody's Seamfree Undershort comes in 6 and 10 inch, as a slip short in 79% viscose from bamboo. Boody's boyleg and BAMBOO COOL's boyshort are short-leg, so they will not stop thighs touching. BAM makes bamboo boxers for men, and its women's midi short does not state a leg length.

What is the downside of bamboo fabric?

Three real ones. It is fussy in the wash, wanting a cool cycle, no fabric softener and air drying, and it loses its softness if you tumble dry it. It costs more per pair than cotton. And because nearly every pair contains elastane, it is not biodegradable, whatever the packaging suggests. The fourth downside is the category itself, which over-claims heavily.

Is bamboo underwear antibacterial?

No. The compound sometimes credited to the growing bamboo plant does not survive the manufacturing process that turns bamboo pulp into viscose, so it is not in any finished bamboo viscose garment. Any brand claiming otherwise is over-claiming, and it has been the subject of regulatory action in the United States. We used to make this claim ourselves and we were wrong.

Is bamboo underwear hypoallergenic?

Not in any substantiated sense. Bamboo viscose is smooth and, when dyed to OEKO-TEX Standard 100, tested for harmful substances. Many people with sensitive skin get on well with it. That is different from a hypoallergenic claim, which is not supported for this fabric.

Is bamboo underwear actually sustainable?

It is complicated and worth being sceptical. Bamboo grows fast and regrows without replanting, and closed-loop production recovers most of the solvent and water used. But viscose is a chemically processed fibre, most bamboo garments contain elastane so they are not biodegradable, and the water-saving percentages that circulate are uncited. Look for closed-loop production and OEKO-TEX certification rather than the word "eco-friendly".

What does "viscose made from bamboo" actually mean?

Bamboo pulp is dissolved and re-spun into a fibre. The result is viscose, chemically the same class of fibre as rayon. It is soft and breathable, and it is not raw bamboo. US Federal Trade Commission guidance is that labels should say viscose or rayon rather than just bamboo, which is why we write "bamboo viscose".

How should I wash bamboo underwear?

Cool wash, inside out, with similar colours. No fabric softener, as it coats the fibres and reduces breathability. Air dry rather than tumble dry. This applies across nearly every brand here, not just Flissie.

Which bamboo underwear brands are UK-based?

Flissie, BAM and Spairs are UK brands, and Marks & Spencer is a UK retailer. Step One is Australian but stocked at John Lewis with UK shipping. Boody is Australian with a UK site. BAMBOO COOL sells mainly through Amazon.

Is bamboo underwear worth the extra cost over cotton?

If you want a smoother feel and faster drying, most people say yes. If you want the lowest-maintenance option, cotton is more forgiving in the wash and cheaper. We go into this properly in our two years of wearing bamboo viscose instead of cotton.

What is the best plus size bamboo underwear?

None of the seven here goes above UK 30. Flissie women's bamboo boxer shorts (we make them) run from UK 8 to 30 at the same price in every size, and Boody goes up to 4XL, which is UK 22. Above UK 30, Snag runs to UK 36 and Chaffree to UK 34, though neither is bamboo viscose.

Should I size up or down in bamboo underwear?

It depends on the brand, so read each size chart. BAMBOO COOL advises sizing down because of the stretch, while for Flissie women's bamboo boxer shorts (we make them), which run from S (UK 8 to 10) to 3XL (UK 28 to 30), we say size up if you are between sizes. The size swap on your whole first Flissie order is free.

Related reading

• Bamboo viscose vs cotton underwear, two years in
• Best women's boxers: 10 brands compared
• Best anti-chafing underwear: 5 long-leg options
• Cotton underwear for women: what to look for, and when it wins