Well...?
In short, yes, but 75% may be more of a rounded figure (it's actually even less).
And we'll prove it.
We punch above our weight
A Sustuff toothbrush head weighs only 3.74g.
Bamboo toothbrushes will vary depending on the retailer, some are thicker than others for an improved grip but weigh 17—20g on average. If you take a Colgate Bamboo Charcoal toothbrush as an example, its listed details actually put it at a slightly lower weight of 16g.
Now, assuming the bristles are the same weight (and they barely weigh anything), this actually makes a Sustuff toothbrush 23% the weight of the lower average range as given above.
In relative terms, that means you could have 4 Sustuff toothbrushes for every 1 bamboo toothbrush.
This is the last mathematical example, we promise
Imagine that Earth has 5 fields available, for which regular bamboo toothbrushes (of the above average weight) require 4 of them. Sustuff only requires 25% of this, so 1 field.
That means that Sustuff can leave 4 out of the 5 fields free and natural, as opposed to 1 natural field for full-bamboo alternatives.
In short, Sustuff would preserve 300% more nature.
So the maths looks legit, big deal. What does that mean for an eco-friendly toothbrush?
You may ask:
"Who cares?" - Some people
Well, the planet probably does but unfortunately we cannot ask it.
Less bamboo (and materials in general), means less deforestation and monoculture of land, less emissions generated for transport and harvesting, less biodiversity affected and more natural stuff left as it should be.
Being eco-friendly is all about leaving nature as-is and doing what we can to mitigate the harmful effects of mankind. This is the same case for toothbrushes as all other things.
Read about that in more detail here, and be reassured that there's nothing sus about our stuff - despite the name. The sus actually stands for something else...
Sources
1. Sustuff (2023) The trusty (and impartial) Sustuff weighing scale, accurate to 0.01g. Sustuff, 15 July
2. Kevin Jones (2023) How Much Does a Toothbrush Weigh? (Plastic, Bamboo & Metal). Measuringly, 23 September
3. Colgate (2020) COLGATE - Bamboo Toothbrush with Charcoal Infused bristles - Medium Toothbrush - Handle Made from Biodegradable Bamboo, 100% Natural - Promotes Good Dental Health. Amazon UK, 24 May
4. Sustuff (2024) Are Bamboo Toothbrushes Really Sustainable? Unveiling the Environmental Impacts. Sustuff, 2 March