The Lumen next to the app
The Lumen next to the app
purple Lumen logo

We test and review fitness products based on an independent, multi-point methodology. If you use our links to purchase something, we may earn a commission. Read our disclosures.


  • Metabolism tracker
  • Measures CO2 from breath
  • Determines if body is using fats or carbs
  • Small, hand-held device
  • Long battery life

In-Depth Review

Lumen Review 2024: A Metabolism Tracker That Works?

Lumen Review 2024: A Metabolism Tracker That Works?

Read the full review.

Pros & Cons

What we like ...
  • Makes me more mindful of what I’m eating
  • Portable and easy to take places
  • High-quality hardware
  • Sleek packaging and aesthetically pleasing
What needs improvement ...
  • Expensive; almost $250 for 6 months of use
  • Cannot be used without the subscription service
  • Integrations are limited

Product Summary

The Lumen is an expensive hand-held device that looks to make people more conscious of what they’re putting into their bodies on a daily basis. However, the price tag is a steep one; for just 6 months of use, you’re looking at paying close to $250 (and it obviously only goes up from there).

If you’re looking to figure out if your body is burning fat or carbs for weight loss purposes, you’ll likely really appreciate what this device has to offer. The connected app will tell you what type of food you should be eating that day based on what your body is currently using as fuel. I think that the app could offer more concrete food plans as a next updated step, but the simple suggestions and daily Flex Score are fun to see.



Lithium polymer battery

Connection for charging




Battery Charge

Lasts up to 14 days w/out charge


Between $249-$349


Apple iPhone 6 and later; Android


102mm x 41.4mm x 33.3mm

GGR Community Reviews


Tried it? Review this product

Leave a Reply

Your email address will not be published.

Use one of the allowed file type: jpg,png,gif. The max size allowed is : 5 MB.


      All in all, I think the Lumen could really work for specific people to be more conscious about what they’re putting into their bodies.