Why I don’t recommend kegg as a fertility tracking device
Fertility tech (FemTech) is booming right now. Devices promise to “take the guesswork out” of ovulation tracking with algorithms, sensors, apps, and colorful charts. One of the most heavily marketed devices in this space is kegg — a vaginal device that claims to identify fertility by measuring electrical impedance in cervical mucus.
At first glance, it sounds impressive. But when you look more closely at the science behind it, there are several reasons many fertility educators, clinicians, and evidence-minded users remain skeptical.
The Core Problem: It Measures an effect of an effect
Kegg does not directly measure ovulation. It also does not directly measure reproductive hormones like estrogen, progesterone, or LH. It doesn’t even really measure your cervical mucus, which is an effect of estrogen.
Instead, it measures electrical impedance in cervical mucus — essentially how easily a tiny electrical current travels through vaginal fluids. The theory is that electrolyte changes in cervical mucus correlate with hormonal shifts throughout the cycle.
That’s a very indirect measurement.
In fertility science, the further you get from directly observing the biological event you care about, the more room there is for error. Cervical mucus itself is already a sign of hormonal changes and can vary around your ovulation day by up to 6 days. Electrical impedance is then trying to measure changes within that sign. That creates a lot of opportunities for noise and inconsistency.
The Research Base Is Extremely Small
One of the biggest red flags is how little independent research exists on this technology.
The main modern study frequently referenced by the company included only 14 women over a small number of regular cycles. Small pilot studies can be useful for generating hypotheses, but they are nowhere near enough to establish strong clinical reliability. The study left out women who are postpartum or who had other hormonal imbalances.
There is also very limited long-term independent validation comparing kegg against established fertility biomarkers across large and diverse populations.
That matters because fertility tracking becomes much more complicated in real life - postpartum cycles, breastfeeding, PCOS, perimenopause, irregular cycles, cervical inflammation, medications, and stress are all things that can affect fertility tracking.
A technology may appear promising in a tightly controlled pilot study while performing much less reliably in actual users.
The Marketing Often Sounds More Certain Than the Evidence
Another reason I don’t recommend kegg is the gap between the confidence of the marketing and the strength of the science.
The device is often promoted as “predicting fertility,” identifying the “full fertile window,” removing “guesswork,” and detecting fertile mucus “more accurately.”
But the underlying evidence simply is not robust enough yet to support very strong claims.
Being FDA-registered also does not mean the device has been proven clinically superior or highly accurate. “FDA registered” is often misunderstood by consumers as meaning “FDA approved and extensively validated,” which are very different things.
Fertility Awareness Already Has Established Methods
Well-established natural family planning methods — like the Marquette Method — are based on decades of research and standardized protocols. These systems teach women to observe actual biological signs directly. Kegg attempts to replace user observation with an algorithm interpreting electrical signals.
That may sound more “high tech,” but more technology does not automatically equal better science.
In fact, reducing fertility awareness to an opaque algorithm can sometimes make women less informed about their own physiology rather than more informed.
I’m all for innovation and advancing natural family planning. But it has to be based on strong evidence and not just a mad dash for profits.
User Experiences Are All Over the Place
If you look through fertility forums and Reddit discussions, you’ll find dramatically mixed experiences. Some users love it. Others report that predictions seemed inaccurate, confusing, or disconnected from confirmed ovulation patterns. Some mention needing LH sticks or temps to figured out if the kegg results were accurate.
That inconsistency raises important questions:
How much relies on prediction algorithms?
How reliable is impedance tracking in varied physiologic situations?
Is this device even useful for anyone outside the “normal cycle” parameters?
When users routinely need additional methods like LH testing or temperature tracking to confirm what the device is saying, it weakens the argument that the device itself is a major breakthrough.
“Scientific” Does Not Always Mean Clinically Useful
There is some legitimate science showing that cervical mucus changes across the cycle and that electrolyte composition shifts with hormones.
But that does not automatically prove that a consumer device can consistently translate those shifts into clinically reliable fertility predictions. Again, a study with 14 people in regular cycles cannot be extrapolated to the entire population.
And unfortunately, women’s health technology has a long history of products being sold with far more confidence than the underlying research actually supports.
The Bottom Line
Kegg may eventually prove useful as an adjunct fertility tool. But right now, the evidence base remains thin, the claims often outpace the data, and many users report inconsistent experiences. Consumers should approach FemTech with healthy skepticism rather than assuming it is a scientifically settled breakthrough. Remember, these companies are trying to make a profit.
Tracking your own cervical mucus may seem daunting, but it doesn’t have to be. The Marquette Method allows for tracking and charting cervical mucus in a simplified way. The Marquette Method also can use temps and LH sticks in addition to fertility monitors. And it’s all backed by evidence.
When it comes to fertility tracking, flashy technology is not a substitute for strong evidence, transparent methodology, and a deep understanding of female physiology. If you’re interested in seeing how the Marquette Method could work for you or what you would need to chart with it, book a free consultation with me today.
