Grin vs Colgate – What's the Best Toothbrush?

Grin vs Colgate – What's the Best Toothbrush?

Posted by Simon Cooper on

In this post I’m comparing Grin toothbrush with a disposable toothbrush from Colgate called the ‘Slim Soft’. 

First off, why did we choose the Colgate Slim Soft? Because it features special, tapered bristles like Grin does.

Most disposable and bamboo toothbrushes use what are called 'flat trimmed' bristles. These are bristles that are cut flat (see the image below). Grin toothbrush and the Slim Soft from Colgate use special, tapered bristles that come to a point. The advantage is that these bristles penetrate deeper between teeth to remove more plaque.

Image showing Tapered vs Flat Trimmed Toothbrush Bristles

What are we comparing?

We’re going to compare 5 features:

  1. Efficacy
  2. Price
  3. Design
  4. Convenience
  5. Sustainability

FYI, this is how we compared the two toothbrushes. We used the Colgate Slim Soft in the morning and the Grin toothbrush at night for a period of one month. That's it. Nothing overly scientific. No wind tunnel testing here!


Since both toothbrushes use tapered bristles, the 'mouth feel' is fairly similar. Both provide a gentle clean that feels kind of plush, or soft. You can definitely tell the difference between these and a cheaper toothbrush with flat trimmed bristles. The feel is much nicer. Both toothbrushes provide a good cleaning. There’s not a lot of difference between how the bristles actually work.

Many of the toothbrushes with flat trimmed bristles are designed with different colour tufts going in different directions. Because of the design of the tapered bristles, this isn't possible.

A few people have told me that they don’t think Grin’s bristles look as effective as some of these more designed bristles. So I did some Googling, because quite frankly, I didn't believe that these crazy-looking bristle designs made any difference.

Turns out I was right!

Here's a study from the US National Institute of Health that tested the efficacy of toothbrushes with angles versus straight bristles. The result?

“Bristle design has little impact on plaque removal capacity of a toothbrush. Both designs are safe enough to prevent GR as long as soft bristle material is used.”

But what about the “charcoal activated bristles?” The Colgate I tested had those black bristles that seem to be trendy these days. I can say I didn't notice any difference in the whiteness of my teeth, but since my testing was with Grin once a day and the Slim Soft once a day, I didn't expect to.

So I turned to Google again and I found a few articles that dispute the effectiveness of charcoal bristles and toothpaste.

Obviously if you spend five minutes online, you'll find articles that claim charcoal is the best teeth whitening solution ever. So I'm going to ignore the charcoal bristles for the results.

Result: Both Grin and Colgate’s bristles do a better job of cleaning your teeth than flat-trimmed bristles.



Grin is priced significantly better than the Colgate Slim Soft, even including home delivery and Grin’s aluminum handle. In fact, as you can see in the table below, Grin costs almost half as much after the first year (when customers get their aluminum handle and 5 brush heads). 

 Brand Price Year 1 Price Years 2+
Colgate Slim Soft $5 per brush head $3.75 per brush head
Grin Toothbrush $6.49 per toothbrush
$6.49 per toothbrush

Dentists recommend replacing your toothbrush every 2 – 3 months, depending on how you brush. So assuming you buy a new toothbrush every 3 months, the Colgate will cost you $25.96 a year. 

A Grin subscription costs $25 for the first year and $15 for subsequent years.

Result: Grin is much less expensive than the Colgate Slim Soft.



Grin is the hands down winner from an aesthetics point of view. The sleek, aluminum handle and simple brush head design is much more attractive than the Colgate.

Photo of a Grin Rose Gold Toothbrush and a Colgate Slim Soft Toothbrush

Beyond how the two toothbrushes look, I also wanted to test how they function.

One of the things I noticed is that after a few weeks, the Colgate toothbrush handle did start to get a buildup of old toothpaste on the handle. This happens because of the little rubbery grooves that they use for grip. Over time, this will start to gather bacteria.

Because of the smooth finish, Grin didn’t collect any toothpaste. A quick rinse under the tap and the handle rinses clean.

Another difference between the two toothbrushes is that the Colgate rolls over when you put it down. The Grin does not. The handle design is flat on the back, which helps it to lay flat and not roll over. This might be a bit nit picky, but I don't love my toothbrush rolling over on the counter since I do brush my teeth in a bathroom... and we know what else happens in there.

Unlike the Colgate, Grin’s brush head is elevated, so when you put it down, the brush head doesn’t touch the bathroom counter. Again, this might be the germaphobe in me coming out, but I'd prefer that my toothbrush stays as clean as possible.

Result: While both toothbrushes do a good job of cleaning my teeth, the Grin wins out on 



The Colgate Slim Soft sells in many major retailers. So you can buy one when you’re out shopping. The challenge with this is remembering when you need a new one. If you're at all like me, remembering to replace your toothbrush every 3 months is NOT top of mind. There are other things I worry about that seem to take up my headspace.

Grin is a direct-to-consumer product, meaning it’s shipped to you in the mail. So buying it is definitely easier. 

Grin also comes with replacement reminders every 3 months. This is super convenient because it means that you no longer have to remember to replace your toothbrush on time.



The Colgate Slim Soft is not a sustainable toothbrush choice. The plastic handle is not recyclable because of the use of several different types of plastic. So after using it for 2 or 3 months, it needs to be disposed of in the garbage and ends up either in landfill, or worse, in our rivers or oceans.

The Colgate toothbrush uses roughly 20 grams of plastic.

The Colgate packaging is a mix of plastic and paper. While both these are recyclable, they very often aren’t.

Grin toothbrush combines an aluminum handle and replacement brush heads. By keeping the handle, Grin uses 85% less plastic than the Slim Soft. Grin’s toothbrush head is also recyclable (although you need to remove the Nylon bristles). 

Grin’s brush head weighs 4 grams, so there is much less plastic being produced and shipped for each toothbrush. 

Result: The net waste from a Grin toothbrush ends up being the Nylon bristles and the metal staples which are used to hold the bristles in place. The entire Colgate Slim Soft ends up as waste.

I've written more blog posts on toothbrush sustainability—this one compares bamboo and plastic toothbrushes with Grin.

Thanks for reading! Feel free to leave a comment below.

If you’d like to learn more about Grin toothbrush, click here.

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