5 STARS UNITED Half-Moon Knee Pillow
Best for: Back sleepers who want gentle, low lift
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 & where to buy
Prices checked 2026-11-01Prices shown were last checked on 2026-11-01 and can change at any time — the price on the retailer's site at checkout is the one that applies. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. 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 price at our recommended retailer as at our last check of that offer (2026-11-01) and, when Amazon reports one, its list price for comparison. Amazon prices come from Amazon's own product data service and are refreshed twice a day; each one shows the date and time Amazon gave it, and one older than 24 hours is replaced by “Check price”. Other retailers' prices are checked by hand and show the date of that check. Retail prices move constantly, so the price on the retailer's own page at checkout is the one that applies. More on Amazon prices
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
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At a glance
How it scores
How our 8.1/10 breaks down — rated on the dimensions that matter most for knee pillows, from published specifications and third-party test data, not the marketing.
Featured in our guides
Buying guides that rank this product
Compare with alternatives
Quick verdicts for the knee pillows most often considered alongside the 5 STARS UNITED Half-Moon Knee Pillow.
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
Everlasting Comfort Under-Knee Pillow review →5 STARS UNITED Half-Moon Knee Pillow vs ComfiLife Knee Bolster for Back Sleeping
The half-moon bolster from the category's bestselling brand — a memory-foam half-cylinder that props the knees to relieve the lower back.
→ Back and side sleepers wanting a trusted-brand bolster
ComfiLife Knee Bolster for Back Sleeping review →Not sure which one is right for you?
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Frequently asked questions
5 STARS UNITED vs Everlasting Comfort?
Both work as under-knee bolsters for back sleepers. 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.