Written By: Lindsay Kuula
Date: June 3, 2025
Updated: October 31st, 2025
Kirkland diapers changed manufacturers and I tested the new version. Unfortunately, they’re significantly worse than before. Full details in the Kirkland section below.

Before I had my son, I thought diapers were just… diapers. You know, a thing that catches poop and pee. I figured I’d use whatever showed up from my baby shower or what I could grab at Target in a bind.

Then I actually became a mom. And realized:

1. Diapers are on your baby 24/7.
2. The wrong diaper can cause leaks, blowouts, rashes, wake a sleeping baby—or worse, have long term effects on your babies health.
3. You’re going to go through thousands of them.

So yes, they matter. A lot more than I expected.

Over the last six months, I tested four popular diaper brands: Coterie, Millie Moon, Costco (Kirkland Signature), and Honest.I wanted answers to the questions every parent asks: Are expensive diapers actually worth it? What’s just clever branding? Which diaper can handle a real-life baby who’s mobile, starting solids, and (hopefully) sleeping through the night?

Here’s my honest breakdown of Coterie vs Millie Moon vs Kirkland vs Honest.

Let’s get into it.

Quick Take: My Overall Winner

Coterie is the clear winner and the only diaper I’m using now after 9 months of testing.

Yes, it’s expensive. But zero overnight leaks, no red marks, the softest material, and the cleanest ingredients made it worth every penny. If your budget allows, this is the best diaper you can buy.

But here’s the nuance:

• Best value? Kirkland (Costco) used to be my budget pick, but they changed manufacturers in January 2025 and are now worse.
• Mid-range option? Millie Moon has decent performance but left deep red marks and indentations on my baby.
• Skip entirely? Honest Company. Tabs ripped constantly and performance was poor.

Quick Comparison Chart

Brand	Price	Aesthetic	Functionality	Clean Factor	Overall
Coterie	$$$$ ($0.50/diaper)	Minimal + Luxe	Exceptional	Cleanest	★★★★★
Millie Moon	$$ ($0.35–$0.40/diaper)	Simple	Good	Clean(ish)	★★★★☆
Costco	$ ($0.18–$0.22/diaper)	Generic	Good	Not “clean” labeled	★★★☆☆
Honest	$$$ ($0.40–$0.45/diaper)	Generic	Poor	Clean(ish)	★★☆☆☆

What I Was Looking For

I wasn’t trying to find the cheapest diaper butI was trying to find the one that worked best for my real life. That meant:

• No leaks or blowouts
• Non-toxic and clean ingredients
• Good fit that didn’t prevent movement or leave red marks
• Low “crinkle factor” and flexibility
• Quick absorbency

About Coterie

Price: $0.50+ per diaper | Buy on Coterie

Coterie is the Rolls Royce of diapers. I’d seen it all over aesthetic mom Instagram (and *ahem* the Biebers using them in their photoshoot for Justin’s newest album) and honestly thought it was another overpriced DTC scam with beautiful branding and a $90+/month subscription.

Coterie was the brand I’d seen on every aesthetic mom’s Instagram and I wanted to try it just for that reason. But, if felt like the branding was too good.

Spoiler: These are, hands-down, the best-performing diapers I’ve used.

What I Loved:

• Legitimately zero leaks, even overnight. Before Coterie, I changed my baby’s diaper at least once during the night, which meant he’d rouse from sleep and take longer to fall back asleep.
• Absorbs fast and keeps baby dry. No wet feeling on his skin.
• No red marks or indents. We’ve all experienced tight socks leaving red, itchy indents on our legs. I hated thinking my baby experienced that 24/7 from his diaper.
• Softest material — feels like cashmere, not cheap plastic
• Super stretchy waistband that moves with your baby
• Monthly delivery = one less thing to remember. They send a 5-day reminder email and the subscription is incredibly easy to adjust. I went online once and had it ship “today” when I was running low. Delivery was within 2 days.
• Cleanest diaper on this list — more details in the clean factor section below

What I didn’t:

• The cost. It’s steep. But if you can swing it, especially for overnights or long stretches between changes, it’s worth it.

Hard Launch Mom Verdict: If you want the best of these 4, this is it.

About Millie Moon

The Target alternative withPrice: $0.35–$0.40 per diaper | Available at Target

Millie Moon is Target’s luxe alternative. The packaging is cute, the materials feel high-end, and it has “clean” marketing (fragrance-free, lotion-free, etc.).

What I loved:

• Softest, most plush material — almost too soft
• Minimal designs (no cartoon characters)
• Affordable and easy to grab at Target in a pinch
• Absorbs well during the day

What I didn’t:

• Left really bad indents and red marks on my baby’s legs and stomach
• Bulkier than others with VERY limited flexibility – preventing mobility
• Hard to put on. No give in the bands, and if my baby had his legs up, it wouldn’t fit correctly. I had to fight to push his legs down for proper placement, which often led to leaks.
• Not great for overnights — had multiple wet sleep sacks and sheets in the morning

Hard Launch Mom verdict: If you want a stylish, clean(ish) diaper at a mid-range price, this is decent. But the red marks and stiff fit were dealbreakers for me.

About Kirkland (Costco) Diapers

Price: $0.18–$0.22 per diaper | Available at Costco

⚠️ IMPORTANT UPDATE (October 2025): In January 2025, Costco switched Kirkland diaper manufacturers from Kimberly-Clark (who makes Huggies) to First Quality (who makes Cuties). I tested the new version, and unfortunately, the quality dropped significantly.

Original Kirkland Diapers:

These were my budget MVP. I look forward to my bi-weekly Costco run, so when a mom friend swore by Kirkland diapers, I gave them a shot and was pleasantly surprised.

What I Loved (Old Version):

• Extremely affordable
• No major leaks during the day
• Decent stretch in the waistband
• Easy to buy in bulk

What I Didn’t (Old Version):

• Slightly stiff/crinkly
• Not fragrance-free or “clean” labeled
• Designs were too “cutsie” for my aesthetic

NEW Kirkland Diapers (Post-January 2025):

After the manufacturer switch, these diapers are worse. Here’s what changed:

Why the New Kirkland Diapers Are Worse:

• Thinner, “paper-thin” material that feels cheaper
• More rashes reported by parents, including complaints about bumpy texture and chemical smells
• Less absorbent — more leaks and wet-throughs reported
• Lost the iconic curved fit that made them comfortable and easy to put on
• Different feel — no longer comparable to Huggies in quality

According to Bloomberg, hundreds of parents have left one-star reviews on Costco’s website describing the new diapers as “paper-thin” and noting increased rashes. A viral TikTok with nearly 100,000 likes shows parents warning about rashes and itchiness from the new formula.

One Costco employee reported a higher number of returns for the new diapers due to quality issues, though Costco says returns are normalizing.

Why Did Costco Change Manufacturers?

Kimberly-Clark (Huggies) decided to exit low-margin private-label contracts to focus on their own premium brands. First Quality stepped in as the new manufacturer, but experts warn they’re unlikely to replicate Huggies’ signature curved chassis design that made the old Kirkland diapers so popular.

Hard Launch Mom Verdict: The old Kirkland diapers (pre-January 2025) were an excellent budget option. The new ones? Skip them. Many parents are switching to Huggies or other brands. If you find old stock somewhere, grab them! But, the new formula might not be worth the savings anymore

About Honest Company

Price: $0.40–$0.45 per diaper

I wanted to love Honest. They’re everywhere, the brand markets clean ingredients and conscious parenting. But in practice, these diapers just didn’t perform.

What I Loved:

• Widely available
• Cute(ish) designs

What I Didn’t:

• Every single tab ripped at some point
• Prone to sagging and leakage
• Extremely thin compared to others, which led to reduced absorbency
• Not cheap enough to justify the poor performance

Hard Launch Mom Verdict: Skip. Every other diaper on this list performs better..

Head-to-Head Category Comparisons

Category #1: Price & Value

Coterie: $0.50+ per diaper

• Most expensive, but worth it if your budget allows

Millie Moon: $0.35–$0.40 per diaper

• Mid-range pricing for mid-range performance

Kirkland: $0.18–$0.22 per diaper

• Best price, but quality dropped significantly after January 2025

Honest: $0.40–$0.45 per diaper

• Too expensive for the poor performance

Winner: Coterie (for value relative to quality) or Old Kirkland (for budget-conscious families, but no longer available)

Category #2: Overnight Performance & Absorbency

This is where diaper quality really matters. Leaks at 3am means disrupted sleep for everyone.

Coterie: ⭐⭐⭐⭐⭐

• Zero overnight leaks in 6+ months of use
  • Updated October 31st, 2025 – In September, I did have 3 nights in a row with leaking through the night, i reached out to Coterie to ask what was up with that, they ended up sending me sample pack of the next size up for FREE. And low and behold, that was the issue, no more leaks since then!
• Absorbs fast and keeps baby completely dry
• Never needed a middle-of-the-night change

Millie Moon: ⭐⭐⭐

• Absorbs well during the day
• Multiple wet sleep sacks overnight
• Not reliable for 12-hour stretches

Kirkland (New): ⭐⭐

• More leaks reported since manufacturer change
• Thinner material doesn’t hold as much

Honest: ⭐

• Prone to sagging when wet
• Multiple leaks and blow-outs

Winner: Coterie

Category #3: Comfort & Fit

Red marks, tight elastics, and stiff materials can make babies uncomfortable.

Coterie: ⭐⭐⭐⭐⭐

• No red marks or indents ever
• Super stretchy waistband
• Soft, breathable material

Millie Moon: ⭐⭐

• Left bad red marks on legs and stomach
• Stiff, inflexible fit
• Hard to put on squirmy babies

Kirkland (Old): ⭐⭐⭐⭐

• Curved, ergonomic fit
• Decent stretch

Kirkland (New): ⭐⭐

• Lost the comfortable curved design
• Thinner, less comfortable material

Honest: ⭐⭐

• Thin material, poor fit
• Prone to sagging

Winner: Coterie

Category #4: Aesthetic & Design

For aesthetic-minded parents, how diapers look matters. (Just ask the Biebers!)

Coterie: ⭐⭐⭐⭐⭐

• Minimal, luxe design
• Sophisticated look

Millie Moon: ⭐⭐⭐⭐

• Simple, clean designs
• No cartoon characters

Kirkland: ⭐⭐

• Generic, “cutsie” patterns

Honest: ⭐⭐⭐

• Fun, colorful designs

Winner: In my opinion, I like the minimal design, but this is subjective.

Category #5: Clean Factor & Ingredients

This is a critical category. What’s touching your baby’s skin 24/7 matters for their health.

Before I became a parent, I didn’t think much about what was in diapers. They’re disposable, right? How much could it really matter?

Then I learned that diapers sit against your baby’s most sensitive skin for 12+ hours straight. For literally years. And that thin, delicate skin absorbs whatever chemicals are in those diapers directly into their body.

That changed my entire perspective.

The 5 Most Important “Clean” Criteria to Look For

If you’re already well versed in the non-toxic lingo, feel free to jump ahead to the comparsion table.

When I started researching diaper ingredients, I was overwhelmed. There are dozens of potential chemicals and certifications to consider. But after talking to pediatricians and reading research studies, these are the five criteria that actually matter most for your baby’s health:

1. Total Chlorine Free (TCF)

What it means: The wood pulp used in the diaper’s absorbent core is bleached using zero chlorine. Not even chlorine dioxide (which FYI “Elemental Chlorine Free” or ECF products use).

Why it matters: Chlorine bleaching creates dioxins as a byproduct. Dioxins are highly toxic compounds. The International Agency for Research on Cancer (IARC) classified the most potent dioxin (TCDD) as a Group 1 carcinogen (known human carcinogen) in 1997, while the EPA classifies complex dioxin mixtures as “likely human carcinogens.” They’re linked to hormone disruption, immune system damage, and developmental problems in children. Even trace amounts accumulate in body fat over time.

When diapers are TCF, there are no dioxins created in the manufacturing process, which means zero exposure for your baby.

The reality: Most diapers (including Millie Moon, Kirkland, and Honest) use ECF bleaching, which reduces but doesn’t eliminate dioxins. Coterie is the only brand in these four that’s 100% TCF.

2. Fragrance Free

What it means: No synthetic fragrances, perfumes, or scents are added to mask the smell of urine or poop.

Why it matters: Fragrance” is a catch-all term that can hide dozens of undisclosed chemicals. According to the Environmental Working Group (EWG), fragrance mixtures have been associated with allergies, skin irritation, respiratory issues, and hormone disruption. EWG’s analysis of popular fragranced products revealed that they contain secret chemicals, sensitizers, and potential hormone disruptors—with some products containing up to 24 unlabeled chemicals.

Baby skin is significantly more vulnerable than adult skin. Research published in peer-reviewed dermatology journals found that infant stratum corneum (the outermost layer of skin) was 20-30% thinner than adult skin, making it far more permeable to chemicals. Fragrance compounds sitting against their skin for 12 hours a day, every day, can trigger rashes, eczema flare-ups, and sensitization to allergens.

The reality: All four diapers I tested are fragrance-free, which is the baseline standard you should accept. Never compromise on this one.

3. Lotion Free & Latex Free

What they mean:

• Lotion-free: No petroleum-based lotions, aloe, or moisturizing chemicals added to the diaper’s inner lining
• Latex-free: No natural rubber latex in the elastic waistbands or leg cuffs

Why they matter:

Lotion: While lotions sound nice (softer skin!), they’re unnecessary and problematic. Babies don’t need lotion on their diapers. Why? Their skin produces its own natural moisture. Adding chemical lotions creates unnecessary exposure and can cause:

• Contact dermatitis
• Allergic reactions
• Clogged pores leading to rashes

Latex: Natural rubber latex is a common allergen. While most babies aren’t born allergic to latex, repeated exposure (like 12 hours a day in a diaper with latex elastics) can trigger latex sensitization. Once developed, latex allergies are serious and lifelong. Better to avoid the risk entirely.

The reality: All four diapers I tested are lotion-free and latex-free. This should be non-negotiable.

4. Paraben Free

What it means: No parabens (methylparaben, propylparaben, butylparaben, etc.) are used as preservatives in any part of the diaper.

Why it matters: Parabens are classified as endocrine disrupting chemicals (EDCs) that can interfere with hormone function, meaning they mimic estrogen in the body. Research has linked paraben exposure to potential health concerns:

• Early puberty in girls: A long-running study published in Human Reproduction found that for every doubling in concentrations of parabens in 9-year-old girls, the timing of breast and pubic hair development, as well as their first period, happened one month earlier on average. However, it’s important to note that research findings on parabens and puberty are mixed, with some studies showing associations while others found no significant effects. Parabens are endocrine disruptors, meaning they mimic estrogen in the body. Research has linked paraben exposure to:
• Reproductive system issues
• Potential links to breast cancer (though research is limited and ongoing)

The concern is especially high for babies because their hormone systems are still developing. Their bodies are more vulnerable to disruption during these critical growth windows.

Parabens are also easily absorbed through skin, and diaper areas are particularly absorbent due to moisture and warmth.

The reality: All four diapers I tested are paraben-free. This has become an industry standard, which is great news.

5. Phthalate Free

What it means: No phthalates (chemicals used to make plastics flexible) are used in the diaper’s waterproof outer layer, adhesive tabs, or packaging.

Why it matters: Phthalates are another class of endocrine disruptors linked to:

• Reproductive development issues
• Hormone disruption
• Asthma and allergies
• Behavioral problems in children

Studies have found phthalates in disposable diapers and detected corresponding metabolites in babies’ urine, with a positive correlation between phthalate levels in diapers and urinary metabolite levels. University of Washington research found that every baby tested had detectable levels of at least one phthalate in their urine, with about 81 percent having detectable levels of seven or more phthalates. The warm, moist diaper environment increases absorption through skin contact.

The American Academy of Pediatrics has called for reducing phthalate exposure in children through its Council on Environmental Health policy statements, recommending that families avoid plastics with recycling code 3 (phthalates) and choose safer alternatives when possible.

The reality: All four diapers I tested are phthalate-free. This has also become standard, but always verify! Some budget brands still test positive for phthalates.

The Bottom Line on Clean Diapers

Baseline requirements (all tested diapers meet these):

• Fragrance free
• Lotion free
• Latex free
• Paraben free
• Phthalate free

Where brands differentiate (and where Coterie excels):

• Total Chlorine Free bleaching (vs. ECF)
• Dye-free materials
• Plant-based components
• Third-party certifications
• Transparent ingredient disclosure

Now let’s see how each diaper actually stacks up: I created a comprehensive comparison chart covering 26 different clean criteria:

Category	Why It Matters	Coterie	Millie Moon	Kirkland	Honest
Total Chlorine Free (TCF)	0% chlorine bleaching reduces harmful dioxins	✅	❌ ECF	❌ ECF	❌ ECF
Fragrance Free	Avoids skin irritation	✅	✅	✅	✅
Lotion Free	Reduces chemical additives	✅	✅	✅	✅
Latex Free	Prevents allergic reactions	✅	✅	✅	✅
Rubber Free	Avoids common allergens	✅	❓	❌	❓
Dye Free	Prevents skin irritation	✅	❓	❌	✅
Alcohol Free	Eliminates drying agents	✅	✅	✅	✅
Free of Heavy Metals	Prevents toxic exposure	✅	❓	❓	❓
Hypoallergenic	Minimizes allergic reactions	✅	✅	✅	✅
Dermatologist-Tested	Tested by skin experts	✅	✅	✅	✅
Paraben Free	Avoids hormone disruptors	✅	✅	✅	✅
Phthalate Free	Excludes hormone-interfering chemicals	✅	✅	✅	✅
No VOCs	Avoids respiratory/skin irritants	✅	❓	❓	❓
No Optical Brighteners	Prevents skin irritation	✅	❓	❌	✅
No Animal Testing	Ethical choice	✅	❓	❓	✅
Made in USA	Stricter manufacturing oversight	✅	✅	✅	✅
Third-Party Certifications	Verified by OEKO-TEX®, EWG, FSC	✅	❓	❓	✅
Plant-Based Materials	Limits plastic contact	✅	❓	❓	❓
Transparent Ingredient Disclosure	Full transparency builds trust	✅	❓	❓	❓
Pediatrician Approved	Expert-backed	✅	❓	❓	❓

Winner: Coterie (by a landslide)

Which Diaper Should You Buy?

Choose Coterie if:

• You want zero leaks, especially overnight
• Clean ingredients and safety are top priorities
• You’re willing to invest in the best-performing diaper
• You value soft materials and no red marks
• You want a diaper that lasts 12+ hours without changes

Choose Millie Moon if:

• You want a mid-range option and easy accessibility available at Target
• Budget is somewhat flexible but Coterie feels too expensive
• Your baby doesn’t get red marks easily
• You’re okay with some overnight leaks

Avoid Kirkland (New Diapers) if:

• Your baby has sensitive skin prone to rashes
• You need reliable overnight protection
• You want quality that matches the old Kirkland formula

Avoid Honest if:

• You want diapers that actually work
• Performance matters more than brand name
• You don’t want constant tab ripping and leaks

My Final Verdict: Coterie vs Millie Moon vs Kirkland vs Honest

After nine months of testing (including six months of original testing plus three more months with the new Kirkland formula), Coterie is the winner.

It won or tied in every single category that matters: overnight performance, comfort, safety, and aesthetics. Yes, it’s the most expensive diaper on this list. But for my family, buying a few extra hours of sleep and one less outfit change per night was worth every penny.

The old Kirkland diapers (pre-January 2025) would have been my budget pick. But unfortunately, those are gone, and the new formula is a significant downgrade.

My current diaper choice:

• Coterie exclusively for day and night (9+ months and counting). I do know many parents that use other brands during the day and Coterie at night for budget purposes, which this is a great solution!
• I’ve been using them since my son was 3 months old and will continue until he’s potty trained.

Different families have different priorities. If your budget is tight and Coterie feels out of reach, I’d recommend buying one box to try for overnights specifically. You might find that using premium diapers just at night (and a cheaper brand during the day) gives you the best of both worlds.

But based on performance, safety, and peace of mind? Coterie wins the Coterie vs Millie Moon vs Kirkland vs Honest showdown.

The best diaper is the one that works for YOUR baby. But if you’re asking which one objectively performed best in my 9-month real-world test, it’s Coterie!

Disclosure: This is a review blog which may get compensated for the products reviewed by the companies who produce them. All products are tested thoroughly and I only endorse products I believe in. I am an independent blogger and reviews are based on my own opinions.