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.
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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
Quick verdicts for the knee pillows most often considered alongside the 5 STARS UNITED Half-Moon 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
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
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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.
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 sleepers. Its half-moon shape props the knees from underneath; side sleepers need a between-the-knees contour instead.
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.