What is the sympto-thermal method?
Ever wished your body came with a manual?
Good news—it kind of does! The sympto-thermal method is like decoding your body’s natural signals to understand your fertility, your cycle, and even your overall health. Whether you're curious about your hormonal health, trying to conceive, avoid pregnancy or just want to ditch the hormones, the sympto-thermal method might be your new best friend. Let’s dive into what it is, how it works, and why so many people are loving this body-literacy approach.
The sympto-thermal method is a fertility awareness method that combines the following key core observations:
Basal body temperature (BBT) – your body’s resting temperature, taken first thing in the morning. A slight rise after ovulation due to progesterone
Cervical mucus – the fluid your body produces throughout your cycle, which changes in texture and appearance depending on your fertility status.
Optional observation: Check your cervix position and feel, if you're comfortable. High, soft and open during fertile days.
By tracking them daily, you can confidently identify
· When you're fertile and when you're not.
· The day of your ovulation
· Your luteal phase (time between ovulation and your period
· Any cycle irregularities that could indicate hormonal imbalances
It’s like your body sending you little clues every day!
Who uses it and why?
It’s used by people who want to feel more connected to their bodies, and by those who prefer a natural approach to reproductive health.
People use the method for different reasons:
To conceive naturally – by pinpointing the fertile window.
To avoid pregnancy – naturally and without hormones. For example those coming off birth control who want to regulate their cycle
To understand their cycle – especially helpful for those with irregular periods or hormonal concerns like PCOS, endometriosis, thyroid disorders
Both the cervical mucus and the basal body temperature are natural indicators of your fertile window. We talk about fertile window because the actual time you can conceive during a ‘normal’ menstrual cycle of 26 to 34 days is only 5 to 6 days ie 4-5 days before ovulation and a few hours after ovulation.
Someone who’s trying to conceive might wonder: ‘I the window is so short and I ovulate on day 14 of my cycle, why have I spent so long worrying about getting pregnant when I wasn’t ready for a baby? And why am I not getting pregnant when I time my intercourse on day 14 or around? ‘
1. It’s because we are all different – day 14 for ovulation is an average and can vary hugely amongst women. Ovulation could occur on day 10 of the cycle for some women and on day 19 for others.
2. If you’re using apps, they are just predicting your ovulation based on your previous cycles – and if you happen to not ovulate on day 14 but on day 11 or 18 for example, then it’s easy to miss your fertile window
Obviously, there are many reasons why you might find getting pregnant difficult but knowing your cycle and when you ovulate is a very good start.
Who recommends the method?
The sympto-thermal method is often taught or recommended by:
Fertility awareness educators
Holistic health practitioners
Some midwives and GPs (especially those trained in natural family planning)
It’s not always part of standard medical advice, but more and more professionals are recognising its value—especially for patients who want hormone-free options.
Benefits
Versatile – can be used for both conception and contraception.
Boosts chances of conception by identifying true fertile days
Up to 99.6% effective at avoiding pregnancy with correct and consistent use
Empowering – you learn about your body and you can make informed choices about your fertility.
Hormone-free – no side effects or synthetic hormones.
Cost-effective – once you have the tools, it’s free.
Disadvantages
Requires consistency – daily tracking is key. Taking your temperature everyday can be constraining even annoying and another thing to think about particularly when you’re trying to conceive. Luckily technology is on your sides and there are ways to automate the process using an Oura ring integrated with a fertility app.
Learning curve – it takes time to get confident.
Not ideal for everyone – shift workers or those with irregular sleep may find it tricky.
But don’t worry—there’s support out there, and once you get the hang of it, it becomes second nature.
Getting Started
How does it work?
Starting with the method can feel like learning a new language—but once you get the hang of it, it’s incredibly empowering. Here’s a quick breakdown of what the sympto-thermal method involves:
Take your temperature every morning before getting out of bed. You’ll need a basal thermometer (with 2 decimals - more precise than regular ones) or a wearable thermometer device like the Oura ring integrated with a fertility app
Observe your cervical mucus throughout the day. Is it dry, sticky, creamy, or stretchy like egg white? Each type tells you something about your fertility. Take note of it.
Optional: Mirror and clean hands if you want to check cervix position
Chart your data using a charting app (like Natural Cycles, Flo, Clue, Fertility Friend) or a printable paper chart. Over time, you’ll see patterns that show when ovulation happens and when your fertile window opens and closes.
Be curious and patient
You can learn through books, online courses, or by working with a trained educator. Some clinics and practitioners (like me!) offer guidance too.
Using the Oura Ring with a fertility app:
You can integrate your Oura Ring with a fertility app, most notably with the FDA-cleared Natural Cycles app, which syncs temperature trend data to provide daily fertility status. You can also integrate with Clue and Flo for general cycle tracking and insights, though these do not offer the same level of fertility-specific predictions as Natural Cycles. To set up the integration, you'll need an active Oura membership and the appropriate fertility app, then link the accounts through the settings in the Oura app.
Natural Cycles App
· How it works: Natural Cycles uses your Oura Ring's overnight temperature trend data, which it analyses to create an "absolute value" for your temperature, to calculate your daily fertility status.
Benefits: It is the only app that directly integrates with Oura for fertility tracking, offering both birth control and conception modes.
Requirements: You need to have an active Oura membership and a subscription to Natural Cycles.
Setup:
Download and sign up for the Natural Cycles app.
Open the Oura app, go to Settings, then Data Sharing, and connect the two apps.
Other fertility and cycle tracking apps
Clue: Connect Oura and Clue to get a more holistic view of your cycle, including patterns and insights.
Flo: Use the integration to understand your body during your cycle, helping you manage things like stress, PMS, and fatigue.
Fertility Friends: This integration is not native. You would need to manually export temperature data from Oura or Natural Cycles into Fertility Friend.
Important considerations
Automatic vs. manual data: Natural Cycles provides automatic syncing for temperature data, which is a key benefit for those with irregular sleep schedules. Other apps may require manual input or may not have the same level of data integration.
Accuracy: The Oura Ring's temperature sensor is highly accurate, but your overall fertility prediction accuracy depends on the app and how you use it.
I’m not advertising Oura by the way! It’s just that so far this is the device that I’ve seen my patients use. There are cheaper alternatives to Oura but not all have been clinically validated for the purpose of integrating with fertility apps.
The ones that are validated to date:
· Oura Ring: Integrates directly with apps like Natural Cycles and Flo, allowing for automatic syncing of body temperature data.
Tempdrop: This wearable thermometer and its accompanying app are specifically designed for tracking basal body temperature (BBT) and fertility.
Ava bracelet: A wrist-worn tracker that monitors temperature and other metrics for fertility tracking and integrates with its own app.
Interpreting your chart
Now that you’re all set up and have started recording, you can start interpreting your data. Your chart will show a rise in basal body temperature after ovulation due to increased progesterone. Here's what to look for:
Pre-ovulation temps: Lower and relatively stable (e.g., 36.2–36.4°C).
Ovulation: A noticeable temperature shift (usually 0.2–0.5°C higher) sustained for at least 3 days.
Post-ovulation temps: Higher due to progesterone (e.g., 36.6–36.8°C).
Menstruation: Temperatures drop again as progesterone falls.
This pattern helps you confirm ovulation after it has occurred, which is key for both conception and contraception.
Cervical mucus types & hormones
Cervical mucus is a fluid secreted by the cells in the cervix — and it changes throughout the menstrual cycle under the influence of hormones. Think of it as your body’s natural fertility tracker.
When oestrogen rises in the first half of the cycle, the mucus becomes more abundant, stretchy, slippery, and clear — that’s your body getting ready for ovulation. This kind of mucus helps sperm survive and swim more easily toward the egg.
After ovulation, the hormone progesterone takes over, and the mucus dries up or becomes thicker — it literally creates a kind of “plug” at the cervix that blocks sperm from entering. Basically, your cervical mucus transforms from a “welcome’ mat to a “sorry we’re closed” sign.
What does fertile mucus look and feel like?
Your mucus goes through several stages:
Right after your period: it might feel dry or sticky. Some people don’t see much at all.
As oestrogen rise, it becomes creamy — like body lotion. That’s a sign your body is getting ready to ovulate.
Close to ovulation: it becomes clear, stretchy, and slippery — like raw egg white. This is peak fertility!
After ovulation: it dries up again or becomes thick and pasty.
And it’s not just about what you see — it’s also about what you feel. Pay attention to how things feel down there:
Dry?
Moist?
Wet?
Slippery?
That sensation is just as important as what you see.
Hormonal Fluctuations & What They Mean
Follicular Phase (Day 1 to Ovulation):
Oestrogen builds.
Mucus becomes fertile.
Temperature stays low.
Ovulation:
Oestrogen peaks.
Fertile mucus is at its most noticeable.
LH surge triggers ovulation.
Temperature rises within 1–2 days.
Luteal Phase (Post-Ovulation):
Progesterone dominates.
Mucus dries up.
Temperature stays high.
If no pregnancy, progesterone drops and menstruation begins.
Practical tips for beginners
Starting something new can feel overwhelming—but the sympto-thermal method becomes second nature with a little practice. Here are some simple tips to help you ease into it:
1. Set a morning routine and start charting on day 1 of your period.
Take your temperature at the same time every morning, ideally after at least 3 hours of uninterrupted sleep. Keep your thermometer by your bed so you can take it before even sitting up.
2. Use a charting app you like
Apps like Natural Cycles, Clue, Flo, or Fertility Friends make it easy to log your data and spot patterns. Choose one that feels intuitive and lets you customize your observations.
3. Check mucus when you use the toilet
You don’t need to do anything invasive—just observe when you wipe. Pay attention to how it looks and feels: is it dry, sticky, creamy, or stretchy? Record daily, even if it’s “dry.”
4. Be consistent, not perfect
Missed a temp? Forgot to check mucus? That’s okay! One or two gaps won’t ruin your chart. Just aim for consistency over time and be kind to yourself as you learn.
5. Learn the “why” behind the signs
Understanding how oestrogen and progesterone affect your mucus and temperature helps everything click. You’re not just tracking—you’re learning your body’s rhythm.
6. Give yourself 3 full cycles to learn
It takes time to get confident reading your signs. Most people feel much more comfortable after 2–3 months of consistent charting.
7. Find support
Consider working with a fertility awareness educator or joining an online community. Having someone to ask questions can make a big difference.
8. Avoid interpreting too soon
Don’t stress about interpreting every little change in your first cycle. Just observe and record. Patterns will emerge with time.
9. Use a backup method if avoiding pregnancy
Until you’re confident in your charting and interpretation, use a barrier method (like condoms) during your fertile window.
10. Ask questions!
There’s no such thing as a silly question when it comes to your health. If something’s unclear, reach out to a practitioner or educator who can guide you.
Final thoughts
The sympto-thermal method is more than just a method—it’s a way to reconnect with your body and take charge of your reproductive health and this is why I recommend it to everyone.
In my practice, my patients and I use the method to check how their acupuncture treatments are working on the regulation of their hormones: more stable, longer, shorter follicular or luteal phases? Clear signs of ovulations? It’s all there, on the charts.
If you want to know whether the sympto-thermal method is right for you, feel free to reach out—I’d love to help you get started!
And if you would like to know how acupuncture can help support hormonal balance and fertility, please email me at Sophie@silverwoodacupuncture.co.uk. We can book a call and I can answer any of your questions.