DECEMBER 2022 UPDATE: As of December 2022, Tempdrop no longer retroactively changes temperatures. While this will improve some of the issues described below, it is still to be seen if it improves others.
Although I did not know it as “Fertility Awareness”, I’ve known about cycle charting since 2008 when I discovered Fertility Friend while dealing with irregular cycles. It wasn’t until 2014 while going through my PCOS diagnosis that I learned more about Fertility Awareness. For years, I put off committing to it because I didn’t think I could make a habit out of taking my temperature every morning. Especially because I’m not at all a morning person and I will sleep as long as possible. And I have not had a consistent wake schedule for large portions of my life.
In 2017, I finally decided to take the leap and fully commit to learning to chart my cycle in 2018. I spent a month researching thermometers beforehand. Because I wanted to be able to do it right and make the commitment easier on myself. I read posts in Facebook groups, I read blogs, I read every review I could find. And I finally settled on the Tempdrop, which I purchased in January 2018. At this point in time, it had only been on the market for about 6 months.
What is Tempdrop?
Tempdrop is a wearable thermometer that uses multiple sensors to algorithmically determine your body temperature throughout the night. I’m not going to go into too much detail on how it works. I’m not going to be able to explain it better than Tempdrop explains it themselves. What this ultimately means is that, at night before you go to bed, you put on the Tempdrop sensor. You can put it either in a sleep bra against your side, or on the provided band high up on your arm near your armpit. In the morning when you wake up, you take it off and sync it to the Tempdrop app.
This means you don’t have to wake up the same time every morning. No need to set alarms to make sure you get that temperature taken the same time every day. Didn’t get at least 3 hours of sleep before waking up? No problem! Since Tempdrop measures throughout the night and uses algorithms to determine your sleeping temperature, you don’t have to create the same habits you would for a regular basal body thermometer.
This is really why it’s so popular and why I took the leap into Fertility Awareness in the first place. It’s a huge selling point!
My Experience with Tempdrop
I struggled for a long time with how to write this review. I don’t know that I would have been able to jump into Fertility Awareness as confidently without Tempdrop. But after over 3 years of use, I have to be honest that along the way, I fell out of love with it.
Originally, the Tempdrop algorithm meant that all of your temperatures could change every day. I would have to go back over my whole chart and double check every temperature against the Tempdrop app to make sure they matched. At the time, Ovuview was the only app that Tempdrop would sync with for automatic charting. And it is only available on Android. It took time every day to adjust my temperatures on my chart but I didn’t mind it so much. And most of the time I didn’t bother checking more than 6-10 temperatures back, since that’s all I needed to identify a temperature shift.
At first my charts looked amazing with Tempdrop. My patterns were so smooth. And just the experience of identifying ovulation time after time was so incredible. About 9 months in, Tempdrop changed the algorithm so that only the past two temperatures would change. Which is still currently how it works. Now, instead of every temperature, I only have to check the last 2 days. This seemed to be a turning point in my experience with Tempdrop. My charts weren’t as smooth. I was starting to notice that in some cycles, the beginnings of my temperature shift seemed to disappear and then reappear a few days later. And shifts were not as aligned with my peak cervical mucus as I thought they should have been.
I started to feel a little skeptical
A year and a half in, I bought my first oral basal body thermometer and started charting it side by side with Tempdrop. The first cycle was great, my temperatures were fairly smooth with both thermometers, and my shifts aligned.
The second cycle I experienced exactly what I feared was happening. My initial shift with Tempdrop adjusted down and reappeared days later. Days after my temperature shift had already been fully confirmed with my oral temperatures.
After 38 months and 33 cycles of charting, I have 14 full cycles of side by side charts to compare. Of those 14, 9 of them look very similar to the one above. With Tempdrop showing a later temperature shift than my oral temperatures. That’s a whopping 64% of charts confirmed with oral before Tempdrop.
Here’s why this is a problem
If you are someone who is trying to avoid pregnancy (TTA), it is recommended not to trust your Tempdrop temperatures until the algorithm has stopped adjusting them 2 days later. Based on my example above, with the oral temperatures, I would have been safe to have sex without risk of pregnancy starting on cycle day 30 when both my temperature shift and peak mucus were confirmed. If I were only charting with Tempdrop, I would not have been considered safe for sex until cycle day 36. A full 6 days later than when I was safe with my oral temperatures. My post-ovulatory infertile phase with oral temperatures is 12 days, but only 6 with Tempdrop. For many couples this would be very frustrating. And could even strain the relationship if abstinence is being practiced, as perfect-use of fertility awareness requires.
This is less problematic for someone who is trying to conceive (TTC). It might mean believing you’re fertile for longer than you actually are. But at the worst it could mean inaccurate conception and due dates, which for some people may mean unnecessary medical interventions.
How common is this issue?
Well, the truth is, there’s no way to know at this point. To this point, Tempdrop has never done any studies to compare it to other modes of temperature taking. Nor has it been studied for efficacy with any Fertility Awareness Based Method. Most people only chart with one thermometer. However, I do know a handful of people who have experienced the exact same issues I have. Some of them being clients and others being other Fertility Awareness Educators. I would speculate that it’s a more common issue than is known. Simply because most people chart only with Tempdrop and don’t compare it. I have seen the same signs in others’ charts that I was initially seeing in mine that lead me to do the side by side comparisons.
I reached out to customer support
When I tried to bring my experience to the attention of Tempdrop Customer Support I was left a little discouraged. This is part of their response:
The tech team has investigated your data and it generally looks good overall. We understand that you’ve experienced an unusual temp pattern and it’s been difficult to interpret your cycle. From what our tech team has seen, this isn’t due to unstable data and these temps are your nightly sleeping temperatures.
They continued to say that they were interested in learning more about why my charts were not aligning and asked for more information on my cycles and charting habits. At the time, I felt quite frustrated as an experienced charter having my understanding of my charts and my cycles being questioned in lieu of responsibility being taken for the product not working right for me.
At the time of this email I had just completed the example chart above, the first evidence of my issues. And so I decided to wait it out and continue my side by side charting to make sure I wasn’t jumping to conclusions. I wanted to have solid data to send to Customer Support when I contacted them. In the meantime, I started to be more vocal about my experience and why I could no longer recommend Tempdrop as a first choice.
Where I Am Now
About 6 months after my email exchange with Customer Support, they reached out to me again via Facebook. I explained everything more in depth since I had more charts completed. And I agreed to send my comparison charts with more detail. More than a year has passed since then. I think often about getting that information together to send but so many things have gotten in the way.
I lost my Tempdrop for a couple of months due to the frame breaking, which is a whole other issue. After a few cycles, I switched oral thermometers and wanted more comparison data with the same thermometer for a reasonable amount of time. And I’ve experienced longer than normal cycles due to my PCOS. I am working now on getting those charts together with explanations to forward to Customer Support. And I hope to have an update here once they’re able to look at all of it.
I’ve had other issues with Tempdrop that would be too much to get into right now. Namely, frequently breaking sensor frames, which seems to have finally been corrected with the latest model. And false temperature shifts, which are more problematic than delayed temperature shifts. I am waiting to write about that until I’ve been able to get my charts to Customer Support.
I’ve been criticized in Fertility Awareness communities on Facebook for speaking out against Tempdrop and failing to get my charts and Tempdrop logs to customer support. Although I do not owe anyone an explanation, I’m going to explain anyway so that maybe people will remember to choose compassion for the strangers they interact with on the internet. When I began having these problems and speaking up about it in 2020, we were in the middle of a worldwide pandemic and I was dealing with job changes because of it. I began compiling the information even before I wrote this review.
However, 2021 was an incredibly difficult year for my family. Two months after writing this review I found out I was pregnant; I struggled with health issues and ultimately miscarried 2 months later. I also miscarried my second pregnancy a few months after that, and shortly after, my father in law passed away. I won’t apologize for putting myself first.
In the midst of my grief and recovery I did manage to finish compiling the information Tempdrop customer support was asking for, as well as my thoughts about why the issues may be occurring for some people. I sent the email to them on January 3, 2022. As of today I still have not gotten a response.
In this time I have continued to see false and delayed temperature shifts in others’ charts, including some of my clients. Tempdrop is not backed by research or science. It is a fallible device that works great for some, and really poorly for others. And you just don’t know which camp you’re in unless you use another thermometer at the same time to compare. I cannot in good conscience recommend it to anyone serious about using Fertility Awareness. Continue reading for my other recommendations.
Is Tempdrop Worth it?
I do want to be clear that I’m speaking only of my own experiences. Although I know of others who have had similar issues, I can’t speak to their experiences. And I truly don’t believe that the majority of Tempdrop users will have these issues.
I wanted to speak out about my experience to hopefully improve others’ experiences with Tempdrop and with Fertility Awareness. There are lots of people who could not chart the symptothermal method without Tempdrop due to their schedules or what have you. I am in no way trying to downplay that. Tempdrop is worth it for a LOT of people. I fell out of love with Tempdrop but it will probably always have a special place in my heart for giving me a good reason to finally start charting my cycle.
What I Recommend
As a Fertility Awareness Educator, my first recommendation is to try charting with a standard basal body thermometer. Even if you have an irregular schedule. Lots and lots of people are still able to get usable charts even without following the standard guidelines to “take your temperature the same time every day after at least 3 hours of sleep”. If you don’t get a full 3 hours of sleep before you wake up, and even if you can’t wake up the same time every day, try taking your temperature with your current schedule for a couple cycles and see what your pattern is like.
If your temperature patterns are difficult to interpret, read through my Basal Body Temperature Troubleshooting Guide to see if you can improve your patterns on your own. You might also consider consulting with a Fertility Awareness Educator to get some personalized tips on troubleshooting. Depending on your situation, this could mean changing your temperature taking time to be more consistent. Or simply switching to vaginal temping.
Consider choosing a method without temperatures
It’s a common misconception that fertility charting requires basal body temperature. But there are actually several other methods that don’t require temperatures at all that are just as effective as the symptothermal method (BBT and mucus). The two top temperature-free methods I recommend are the Billings Ovulation Method® and the Marquette Method.
The Billings Ovulation Method® is one of the oldest methods around and is what most other methods with a mucus component are based on. It is considered a “cervical mucus only” method. The primary fertility sign charted is the sensation that cervical mucus creates at the vulva, with appearance of mucus being charted secondary to sensation. It is very different from standardized mucus categories that symptothermal methods provide. The guidelines for identifying ovulation based on sensation is much more stringent than other methods. And it’s backed by dozens of research studies and nearly 900,000 hormonal assays.
The Marquette Method is taught by health professionals and focuses mainly on urinary hormone values. It utilizes the ClearBlue Fertility Monitor and is much less subjective than most other Fertility Awareness Methods. It’s a great option for postpartum moms (as is Billings) but does require morning urine testing within a certain window of time. It also has optional temperature and cervical mucus guidelines so you could add temperature back in at a future point if you wanted to.
The bottom line
I only recommend Tempdrop as a last resort if all else fails. There are LOTS of options out there that could make a difference in your charts. Whether it’s a different method or a different thermometer. For me, changing from a 1 minute thermometer to a 3 minute thermometer made a huge difference in the stability of my temperature patterns.
If you still want to use Tempdrop
Lots of people still choose to go with Tempdrop. There’s absolutely nothing wrong with that. My experience has not been proven to be the norm. And overwhelmingly the majority of Tempdrop users are happy with their experiences.
I do have some recommendations for you if you decide to purchase the Tempdrop. First, make sure you know what you’re getting into. So many people buy Tempdrop without being aware that the algorithm means temperatures changing on a daily basis. I highly recommend reading their How it Works page as well as their Frequently Asked Questions so you know what to expect. Also check out this in depth FAQ that I helped organize.
Second, when you’re ready to purchase, make sure you’re getting a good deal. You can get a discount on the Confidence and Freedom packages with my referral link. You can also sometimes find it on sale on Amazon. You can learn more about the differences between these packages on their website and the FAQs linked above. If I were to purchase Tempdrop again, I would definitely go with the Freedom package. This includes the extended warranty and Tempdrop Care. I have needed both throughout my 3+ year experience. That is pretty typical, so you may as well spend that money up front instead of having to purchase a new Tempdrop later.
Third, and in my opinion the most important for your charting experience: use a standard basal body thermometer for at least 3 cycles when you start using Tempdrop. The algorithm needs time to learn your patterns and it’s not reliable right away. And if you happen to be one of the few who don’t have good experiences with Tempdrop, you’ll want to see that right away by comparing your temperatures side by side for several cycles. With the Confidence and Freedom packages you can return the Tempdrop within 1 year if you’re not happy with it for any reason.
If you’re hesitant to try Tempdrop
That’s okay too. Check out my list of recommended basal body thermometers for other options. My favorite, hands down, is the Femometer Vinca II. And if you’re just not sure, never hesitate to reach out with questions. Or schedule a free consultation for feedback on your situation.
Have thoughts about my Tempdrop review? I’d love for you to share them in the comments!
On mobile, you can swipe through my charts to see all of my Tempdrop and oral BBT comparison charts.