How Long Does Bar Shampoo Last? Switch, Save Money, Reduce Waste

Find out how long bar shampoo lasts, why it saves money & waste, plus our top picks for every hair type. So many reasons to make the switch today!

Estimated Read Time: 3 minutes

Thinking about ditching your plastic bottles for a bar shampoo but not sure if it’s worth it? One of the top questions people ask before making the switch is: how long does bar shampoo actually last?

The short answer is around 2–3 months, up to 90 washes per bar, or 3 x as long as most liquid shampoos!

Here’s why that matters.

Benefits Of Bar Shampoos 

Liquid shampoo might look innocent in its glossy bottle, but it’s basically a glorified water balloon. Most formulas are up to 80% water, which means you’re not just buying shampoo, you’re paying to haul water around the globe!

Then there’s the packaging problem. Every year, a whopping 550 million plastic shampoo bottles are tossed in the U.S. alone. That’s enough to build a plastic mountain no one wants to climb.

And the ripple effect? All that extra water weight and plastic means more fuel, more emissions, and more waste.

Now imagine skipping all that nonsense. Bar shampoo is the concentrated, travel-friendly, no-nonsense alternative. No water filler, no bulky bottles, just a compact little powerhouse that lasts for months.

The concentrated formulas save you money by giving more washes for the cost than bottled formulas!

Here’s the quick rundown of benefits:

• Less water wasted: no unnecessary fillers, just concentrated cleansing power.
• Less plastic waste: every bar replaces about three plastic bottles.
• Lower shipping emissions: lighter, smaller, and easier to transport.
• Money savings: more washes per dollar compared to most bottled shampoos.

Cost-Per-Wash 

A high-quality shampoo bar may seem pricier upfront than a drugstore bottle, but the cost-per-wash is usually lower.

If a bar lasts 90 washes, that’s about 30 cents per shampoo session. Try finding a plastic bottle that gives you that much value. (Spoiler: you won’t.)

Factors Affecting How Long Your Bar Shampoo Lasts

With all that said, a shampoo bar’s lifespan isn’t the same for everyone. Your habits and hair type play a big role in how long it sticks around. Here are the main things to keep in mind:

• Hair length & thickness: More hair = more lather needed.
• Wash frequency: Daily washers will inevitably go through bars faster than 2–3x/week washers.
• Storage: Keep it dry between uses. Leave it in a puddle? Expect a mushy, short-lived situation!

How Long Does ZWS Essentials Bar Shampoo Last?

Let’s get to the specifics. The ZWS Essentials Shampoo Bar is the hero of our zero waste bathroom lineup. Each nutrient-packed bar is designed to last up to 90 washes, which is around 2–3 months of use, depending on your hair type, length, and how often you lather up.

But to give you a taste of what’s possible, here are a few that shine for specific hair needs:

• Bloom – Boosts growth for Rapunzel vibes.
• Maui Melon – Defines curls.
• Driftwood – Soothes dandruff-prone scalps.
• Lotus – Balances oily roots.
• Oasis – Hydrates and smooths in gray/frizzy hair.
• Simply Unscented – Gentle, fragrance-free.

Pro Tips to Make Your Bar Last Longer

Want to stretch those 90 washes a little more? A little TLC goes a long way. The way you store and use your shampoo bar can make a huge difference in how long it lasts, plus it keeps it from turning into a soggy soapy mess.

• Store on a draining soap dish or travel tin with ventilation.
• Cut into smaller pieces (great for travel too) and use a soap saver bag
• Lather in your hands first to avoid overuse.

For more tips, check out our full guide on how to store shampoo bars.

Final Thoughts: Why A Bar Shampoo Is a Win-Win

At the end of the (wash) day, bar shampoo lasts longer, saves money, and keeps plastic waste out of landfills. It’s an easy switch with a big impact on your hair, your wallet, and the planet.

Ready to switch? Explore all ZWS Essentials Shampoo Bars today.