I had a chance to do a head to head test of the Keto Mojo blood ketone meter and the Biosense breath ketone meter during my recent 8-day water fast.
I tested my blood and breath ketones using both multiple times throughout the day. My impression is below.
First, a quick reminder on why I planned to switch to Biosense:
- Less cost: break even at 300 tests, $1.00 per test savings thereafter
- Better accuracy: clinically proven precision vs “within 20%”
- No finger pricking
- Faster: I expected the time to blow and wait for results would be faster than pulling out my gear, pricking, taking a blood drop, and waiting for results
- More convenient: Traveling with all my gear and storing extra strips isn’t a huge deal but I was excited to just slip the Biosense in my purse and be done with it.
Unfortunately, many of my expectations didn’t quite match reality after I was able to try the device.
Here’s how the Biosense compared to my Keto Mojo on factors of:
One quick note: The Biosense measures ketones using a unit called ACEs. 10 ACEs is roughly equivalent to 1.0 mmol/L of BHB blood ketones. 20 ACEs on Biosense roughly equals 2.0 on keto mojo, 30 ACEs approximates 3.0, etc. Just move the decimal point space to translate.
Finger Pricking: Advantage BioSense
The Biosense has the clear advantage here. For people like my sweet husband Brad who hate needles and blood, a breath meter really is the best solution, and Biosense is the only breath meter out there with clinically proven accuracy. In fact, I expect Brad to be the primary user of our Biosense.
However, if you’re tracking your GKI for therapeutic ketosis and not just your ketones, you’ll likely still need to prick for the glucose test. The alternative, which I’ve tried, is a continuous glucose monitor (CGM). A CGM only needs to be inserted every two weeks and will send 8 hours of recorded data to my phone via Bluetooth with just a tap.
Most of the time I’m not wearing a continuous glucose monitor, though – and most therapeutic keoters aren’t either. Instead, I’m using the Keto Mojo as my blood meter and can use the same drop of blood for measuring my ketones, too.
Biosense is therefore generally best in the finger-pricking department for those who are only tracking ketones and not GKI.
Cost: Advantage Biosense
Even though the up-front cost is substantially higher, there’s no incremental cost per test with the Biosense vs the average $1 per ketone test strip cost of the Keto Mojo.
If you plan to test more than 300 times, Biosense really does come out on top.
|Meter Cost||$299||$49 (comes with 10 strips)|
|Cost per ketone test (per strip)||$0||$1|
|Cost after 300 tests||$299||$339|
Time to Test: Advantage Keto Mojo
Ohmygod the Biosense takes so long to test. Over two minutes of noisy “preparing the device” before each test. Then usually 10 seconds to blow and sample, then 20 more seconds to analyze and display the results.
IF it doesn’t automatically start “deep clean” mode which takes well over 5 minutes. After my first day of testing I was in deep clean mode every time.
Note that, you only have a 2 minute 15 second window after “preparing the device” in which to test. If you get distracted and miss that window, you will need to wait over 2 minutes to prepare the device again. At my most focused, each test took 3 minutes.
Keto mojo takes 7 seconds to charge after insertion of a test strip. I usually prick during that time. Less than 5 seconds to register my blood drop and 10 seconds for results.
|Time to charge||135 sec or 305 sec with deep clean||8 sec|
|Time to sample||9 sec||4 sec|
|Time for analyze||20 sec||10 sec|
|Total test time||164 – 334 sec||22 sec|
The Biosense has less to keep track of, which is nice. Just the device itself in its small carrying case if I’m going out for the day. To conduct a test on the Keto Mojo I need the device, strips, and the lancet for pricking, all of which fit in the larger carrying case.
What I didn’t take into account with the Biosense was the fact that it needs to be charged so I need to keep track of it’s micro USB charger. It’s a little more brain space for my nomad life living out of a suitcase and adds the risk of running out of battery.
This could just be a problem with my limited mental bandwidth. The Keto Mojo requires keeping track of strips, the lancet, and backup lancet needles so pick your poison.
Really, it’s just the time investment and noise involved in Biosense testing that keeps me reaching for the Keto Mojo.
Precision: Advantage Keto Mojo
Biosense actually paid for a clinical trial demonstrating its accuracy and I give them points for that. However, a deeper look at that research doesn’t show that it is necessarily more accurate than Keto Mojo. The results of their small trial (19 people) showed that Biosense results correlated strongly with blood meter results. That is to say, they were similar. Interestingly, breath ketone numbers seemed to lag behind blood numbers.
However, I have a real concern with my experience using the Biosense.
Biosense vs Keto Mojo: Precision and Repeatability
The biosense’s readings varied A LOT over the 3-5 minutes it takes to take a repeat reading. From 32 to 40 within 5 minutes and 39 to 25 within 3 minutes… keep in mind that these were all taken after 2 days of water fasting when multiple readings on my keto mojo were showing the same steady, repeated numbers when these readings were taken.
Biosense vs Keto: Mojo Accuracy
Legally, Keto Mojo readings are within 20% of your actual blood glucose. Frequently, Biosense readings differed from the Keto Mojo by more than 20%. Obviously, the truth could be somewhere in-between but it did raise some concerns on my part given that the Biosense differed from its own readings by more than 20% sometimes, as shown above.
Technology: Advantage Biosense
The Biosense comes with a nice app that makes pretty charts, which I like a lot. The device does become untethered from the app seemingly every test but it’s easy to re-tether and I’ve never lost data.
Biosense also integrates with Cronometer, the online tool most therapeutic ketoers use to track their eating and metrics. *
For the ketone mojo, I’ve been keeping track of my numbers in a Google spreadsheet and by manually entering into Cronometer.
* Note that, device data must sync to the Biosense app before it is imported to Cronometer – usually a half day delay or so.
Usefulness: Advantage Keto Mojo
I wasn’t sure what to call this section but the fact is that the Biosense isn’t that useful to me because it doesn’t measure ketones over 40 ACEs, the rough equivalent of 4.0 mmol/L BHB ketones.
Those using keto for medical, therapeutic reasons — especially those targeting GKI less than 1.0 — are usually over 4.0 ketones and need to know how much over to know if their GKI is less than one. The Biosense 40 limit tells you you’re under 1.0 GKI only if your blood sugar is under 72 mg/dL.
Honestly, I’ve maxed out the 8.0 limit on the keto mojo once before but going over 8 mmol/L of blood ketones is incredibly rare and not advised.
You can see how, for me, the straight line chart showing that my ketones measured as ACEs are over 40 is less helpful than knowing when they’re higher or lower in this range.
The Bottom Line: Keto Mojo vs Biosense
Biosense is best for:
- People who are pursuing nutritional ketosis and don’t often need to measure ketones over 4.0.
- People who hate the finger prick
- People who plan to do at least 250 ketone tests and who value money more than time
If this is you, click here for $20 off Biosense! (note that the discount only displays during checkout.)
Keto Mojo is best for:
- People pursuing therapeutic ketosis who spend much of their time in the 4.0+ ketone range.
- Those tracking GKI without a CGM who have to prick anyway.
- People who value time more than money and don’t mind the finger prick.