Kirkland Signature Supreme Review

Signature Supreme is a big-box store brand diaper made by Costco. It has a better than average price, a soft outer cover, and is chlorine, latex, and perfume free. The diaper is available online and in Costco stores, but the better prices can only be had by Costco members. Big box diaper brands are a popular choice because of the perceived value of buying a store brand for a discount that consumers assume is comparable to national well-known brands like Huggies or Pampers.

Performance Comparison

Absorption and Leaks

Kirkland scored below average for absorption, ranking as one of the lowest in our tests for its price range with a 4 of 10. The leak score was marginally better with a 5, but given that Up & Up, a diaper that is cheaper overall, scored the same, it was still a fairly mediocre result. There were diapers that scored worse in our tests for both metrics; diapers that were both cheaper and more expensive demonstrating that Kirkland is just sort of so-so for a diaper in its price range.

Signature Supreme ranked 15 out of 24 for the absorption test tying with Seventh Generation Free & Clear and Luvs Ultra Leakguards. But it did score higher than both for leaks with a 5 compared to their scores of 2 and 3 respectfully; which was a little interesting consider Luvs offers a money back leak guard guarantee.

For diapers in its price range only two diapers scored better for leaks, Pure n Gentle and Pampers Swaddlers Sensitive, each with a 6. And with Swaddlers Sensitive also scoring an 8 for absorption, it made for a better overall diaper. Our test indicated that Kirkland might be able to compete with some of the Huggies varieties like Snug & Dry (with scores of 2 for leaks and 7 for absorption) or Little Snugglers (5 for leaks and 4 for absorption), but it was no match for both Pampers offerings, with Pampers Swaddlers.

The absorption test for Kirkland Signature Supreme (left) versus Pamper Swaddlers (right) are shown below. The larger green area indicates more surface moisture; less green indicates better absorption.

Comfort and Durability

Kirkland scored a 5 of 10 in our tests for comfort. It ranked 14 out of 24 diapers, placing it below average out of the diapers we tested, but almost dead middle for the diapers for its price range. While the Signature Supreme boasts soft materials (and we did give it points for that), we felt the leg cuffs were coarser than other brands and might cause chaffing or discomfort to baby's sensitive inner thighs. It did get extra points for breathability of fabrics and for softer back and side elastic compared to the other diapers we tested. Only Little Snugglers out scored it for comfort in its price range, with green diapers Andy Pandy and Babyganics Rear Gear leading the pack with 9 and 8 of 10 respectfully, but with much larger price tags.


For durability the Signature Supreme did not fair too well with a score of 3, which tied it for last place with Pure n Gentle Ultra out of the diapers we tested in its price range. Cuties, one of our Best Value picks, scored an impressive 8 for durability and a 6 for comfort putting it in front of Signature Supreme for both of these metrics. With a cheaper per diaper price, and a better absorption score that adds insult to injury, it is hard for Kirkland to really shine here. So while it wasn't a diaper that reviewers said fell apart, it wasn't a diaper that fared as well as others.

Eco and Health

Kirkland stands out among its competitors in the baby health metric. Signature Supreme scored a 4 of 10, which was not only the highest in its price range, but was the highest of ANY traditional diaper. In addition, it scored better for health than even some of the green diapers, which is opposite of what we would have assumed before testing. Both green diapers Seventh Generation Free & Clear and Huggies Pure & Natural earned only a 3 of 10 for this metric.

Signature Supreme earned its score by being free of chlorine, latex, and perfumes. And while a score of 4 might seem low, it did outscore 14 other diapers in our tests. Not too shabby for a store brand big-box traditional diaper. Just imagine how awesome they'd be if they shunned dyes and lotions too (hint hint Costco). Overall though, it was hard to find fault with this traditional diaper when it came to health, and if baby's health is your primary concern it is the highest ranking diaper in its price range for this metric. Up & Up has the same score and is cheaper, but its absorption score was only a 3 of 10. You have to go up about some in price to Earth's Best Tender Care before you find a better scoring diaper with a score of 4, or our Editors' Choice winner, BAMBO Nature, with a health score of 8 and 9 for absorption in our tests.

It also scored fairly well for eco-friendly, for a traditional diaper that is. It earned a 2 of 10 for this metric tying with Up & Up for the honor of most eco-friendly non-green diaper. It earned this score primarily for its use of non-chlorine processing.

Best Applications

The budget conscious parent, who is likely a member of Costco, will be drawn to this diaper. With a reasonable price and big-box draw, Kirkland Signature Supreme seems like a good deal on the surface. But it's what's just below the surface that counts, and Signature Supreme failed to impress us with its only average absorption ability contained beneath its chlorine, latex, and perfume free outer cover and liner.

If being on a budget is the driving factor behind choosing Kirkland then one of our Best Value picks, Cuties, is a great option with a better absorption score and similar leak score. It also has a price that is cheaper per diaper. If convenience is a factor, because you can get it with all your other big box purchases, then Huggies Snug & Dry is probably a better buy with a better score in our tests for absorption with a 7, and a comparable price; plus it is usually sold side-by-side at Costco stores. If health and price matter, then Up & Up might be the better buy. The absorption score we got is slightly less, with a 3 instead of Signature's 4, but it has the same health metrics, better eco metrics, the same leak score, and a significantly cheaper price.

Conclusion

Kirkland Signature Supreme is not a terrible diaper scoring a 43 of 100, but it just isn't the best diaper out there. It was hard to get too excited about this diaper with its mediocre test results. In our tests, it just wasn't a stand out. Frankly, if it wasn't chlorine, latex, and perfume free we wouldn't have much to say about it at all, combined that with its other test results, and you have a diaper we would not necessarily recommend.

However, if health is a concern (and for most parents it is), or if you have a baby with sensitive skin, it might just be the best thing going for its price (though Up & Up is cheaper with similar health score). However, that is the key, for its price. If you have some wiggle room in your budget we suggest you consider Earth's Best Tender Care, which scored a 4 for health and a 60 of 100 overall. Yes, it is more expensive on average, but it really is worth the extra money in our opinion if you can afford it. If money is not an issue, we would recommend our Editors' Choice BAMBO Nature, which scored better in our tests overall with a 82 of 100 respectfully.

Other Versions

Kirkland does not make any other diapers. Target's Up & Up will give you a pretty good diaper for a cheaper price, and they even have the same health benefits (chlorine, latex, and perfume free). In the end, it depends on what you are looking for in a diaper. They scored about the same in most categories for our testing, with Up & Up scoring 41 of 100 overall and Signature Supreme scoring a 43. With the exception of absorption, Up & Up had higher scores in every metric.