KNEE PILLOWS·5 STARS UNITED
5 STARS UNITED Half-Moon Knee Pillow
4.4 · 7,952 reviews
Editor score8.1/10
Best for: Back sleepers who want gentle, low lift
Sleeper
Back sleepers
Shape
Half-moon bolster
Fill
Memory foam
The low half-moon bolster — a subtler under-knee lift for back sleepers who find full bolsters too tall, at a friendly price.
The 5 STARS UNITED knee pillow is a half-moon bolster: lower and gentler than a full half-cylinder, it gives back sleepers a modest knee lift that eases the lumbar arch without over-propping the legs. That lower profile suits people who find taller bolsters uncomfortable or who want subtle support rather than a big lift. Firm memory foam, a washable cover, and a low price round it out. With ~8,000 reviews it's well-proven for the gentle-support crowd. It's back-sleeping only, and if you actually need a lot of lift, a taller bolster like Everlasting Comfort will serve you better.
Price across 3 retailers
Prices checked 2026-07-04Prices shown were last checked on 2026-07-04and can change at any time — the price on the retailer's site at checkout is the one that applies. As an Amazon Associate and affiliate we may earn a commission on purchases made through these links, at no extra cost to you.
How our prices work
We show the lowest price we found at our last check (2026-07-04) and the manufacturer's list price for comparison. Retail prices — Amazon's especially — move constantly, so treat these as a guide: the price shown on the retailer's own page at checkout is the one that applies. Tap through to see each retailer's current price.
Should you buy it?
What we like
- Low half-moon = subtle, comfortable lift
- Good for people who dislike tall bolsters
- Firm foam + washable cover
- ~8,000 reviews at a low price
What to know before buying
- Low profile may under-support some
- Back sleeping only
- Not for side-sleeper knee alignment
At a glance
SleeperBack sleepers
ShapeHalf-moon bolster
FillMemory foam
StrapNo
CoverWashable, removable
Best forGentle lumbar lift
ProfileLow
Reviews7,900+
Price~$33
How it scores
How our 8.1/10 breaks down — rated on the dimensions that matter most for knee pillows, from hands-on testing and verified specs, not the marketing.
Alignment support
7.5/10
Comfort
8/10
Breathability
7/10
Durability
7.5/10
Value
8.5/10
Compare with alternatives
Quick verdicts for the knee pillows most often considered alongside the 5 STARS UNITED Half-Moon Knee Pillow.
VS·HEAD-TO-HEAD
5 STARS UNITED Half-Moon Knee Pillow vs Everlasting Comfort Under-Knee Pillow
The back-sleeper's pick — an under-knee bolster that lets the knees bend to flatten the lumbar arch, and the highest-rated pillow here.
→ Back sleepers with lower-back pain
VS·HEAD-TO-HEAD
5 STARS UNITED Half-Moon Knee Pillow vs ComfiLife Knee Bolster for Back Sleeping
The back-sleeper bolster from the category's bestselling brand — a memory-foam half-cylinder that props the knees to relieve the lower back.
→ Back sleepers wanting a trusted-brand bolster
Decision support · what no other comparison site has
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Frequently asked questions
5 STARS UNITED vs Everlasting Comfort?
Both are back-sleeper under-knee bolsters. The 5 STARS UNITED half-moon sits lower for a gentler lift; Everlasting Comfort is taller with more lumbar lift and a slightly higher rating. Subtle support: 5 STARS UNITED. More lift: Everlasting Comfort.
Is a half-moon better than a full bolster?
Only if you find full bolsters too tall or firm. The lower half-moon gives a softer, subtler knee lift — great for light support, not enough if you need to significantly bend the knees for relief.
Back or side sleepers?
Back sleepers. Its half-moon shape props the knees from underneath; side sleepers need a between-the-knees contour instead.
Does it flatten over time?
It uses firm memory foam that holds up reasonably; because it's a low profile to begin with, any softening is more noticeable than on a taller bolster.
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