Charting your Basal Body Temperature every morning could help you work out which hormones may be out of balance and need a little extra support, as well as giving you the empowering ability to understand your own unique menstrual cycle on a deeper level. As we know, unhappy hormones can wreak havoc on our skin, causing it to become more oily and prone to breakouts – whether it’s persistent breakouts that happen throughout your cycle, or regular monthly breakouts that crop up just before Aunt Flo appears – charting your cycle can help you get an idea of where your hormones are at, without spending a fortune on complex hormone tests.
what is basal body temperature?
Your basal body temperature (BBT) is your lowest body temperature in a 24-hour period. The most accurate time to take your temperature is when you first wake up in the morning, before you even sit up in bed.
what is basal body temperature charting used for?
I first came across BBT charting when I was researching PCOS after my initial diagnosis during Summer 2015. It quickly became apparent that BBT charting is a useful tool to understand many different aspects of your cycle and fertility which can give you incredible information about different hormonal imbalances in your unique menstrual cycle.
I’ve been charting my cycles for a while now and during my very first month of tracking it was apparent that my progesterone levels were on the low side. (That’s why I started supplementing with Agnus Castus drops in October).
N.B Basal Body Temperature charting is only going to give you usable information if you’re on non-hormonal contraceptives (Copper IUD, Condoms, Sponges, Diaphragm or ‘Fertility Awareness Method’ < i.e no birth-control!) and are cycling naturally as ‘the pill’ and other hormonal methods of contraception prevent pregnancy by tricking your body into a constant state of ovulation so you don’t release another egg.
how can it help your acne?
Understanding your hormones can be the key to finally working out the root cause of your acne and where your imbalances lie. Are you suffering with an excess of androgens and testosterone? Are you struggling with low-progesterone and oestrogen dominance? Or perhaps, like me, you’re battling a bit of everything! All these hormonal imbalances can cause mild, moderate and severe acne, along with weight gain, insulin resistance, mood swings, fatigue, Hirsutism (excessive hair growth), irregular periods, fertility problems and more.
By charting your BBT you can begin understanding your unique hormonal patterns throughout each cycle and working out which hormones could be the root cause of your problems. Armed with all this data, you will be able to make more informed decisions about which steps to take next in your healing journey.
When I had my copper IUD taken out earlier this year I was desperate to find a safe, totally natural contraceptive alternative. I’ve been charting my basal body temperature since 2015 and it’s such a great tool for understanding your periods and hormones SO MUCH BETTER! Seriously, your temperature first thing in the morning can tell you so much about your hormone imbalances (link in bio for my blog post on this subject)! Anyway, since 2015 I’d been using the Clue app to track my periods and monitor my hormone fluctuations but when I discovered @naturalcycles I knew it was the contraceptive upgrade I’d been looking for! It’s the only certified contraceptive app and has a perfect use Pearl index of 0.5 – meaning 5/1000 women got pregnant in a year – compared to 0.3 on the pill, 0.6 on the copper IUD and 2 using condoms. Pretty great results for something that has ZERO side effects and takes literally 20 seconds to do in the morning! If you’re interested you can get a 10% discount code for the yearly package over on my blog (link in bio)
how to chart your bbt
Although charting your BBT is really easy. You need to follow precise steps to make sure your readings are as accurate and informative as possible. Follow these steps for optimum data:
- Take your temperature on waking after at least 3 hours of sleep.
- Take your temperature immediately on waking, without getting up or moving about too much.
- Try to take your temperature at the same time each day
- Purchase a 2 decimal place digital thermometer. AVOID common thermometers which measure to only 1 decimal place as these are useless for charting BBT.
what is a ‘healthy’ temperature?
The average range of BBTs is between 36.11-36.50C (97.0-97.7F) before ovulation and 36.50-37.22C (97.7-99.0F) after ovulation.
oestrogen, progesterone and your cycle
A healthy, natural cycle is split into two phases, follicular and luteal. Both these phases reflect the hormone dominance of either oestrogen or progesterone with ovulation ideally occurring in-between these two phases, around day 14.
During the follicular phase, oestrogen is the dominant hormone and in a natural cycle, prepares the womb for pregnancy. During this phases your temperature will likely be at its lowest, between 36.11-36.50C (97.0-97.7F).
Mid-way through your cycle, if charting your BBT, you will typically see a ‘spike’ in temperature. The day before this temperature spike is the day you ovulate.
During the second half (luteal phase) of your menstrual cycle (after ovulation) another major reproductive hormone, progesterone, comes into dominance which causes your BBT to rise to 36.50-37.22C (97.7-99.0F). Your luteal phase is usually 14 days in length.
In the lead up to your period, one of two things will happen. In the case of pregnancy, a fertilised egg will implant into the uterus about a week after ovulation. If this happens, the embryo releases another hormone, hCG, which will tell the body to keep the progesterone levels high and prevent menstruation. However, if there is no fertilised egg, then no hCG will be released and your progesterone levels and basal body temperature will begin to drop off and it’s likely that your period will soon start.
See the graph below for a visual reference of how your BBT changes during your cycle:
UPDATE April 2016: During the first few months of tracking my cycles, my BBT during the second part of my cycles was between 35.90 – 36.40C, when ideally it should be between 36.50-37.22C. It was also jumping all over the place and there was no ‘spike’ mid-cycle. After 6 months of taking B-Complex, Magnesium, Zinc and Agnus Castus my app was finally able to recognise a small spike in my cycle and my BBT during the second part of my cycle is now between 36.15 – 36.61 – still a little on the low side but still a big improvement for me. This may not seem like a dramatic difference, but tracking my cycle has really helped me understand my cycle a bit better. Plus with my Clue app I was able to track when I was breaking out. I would log the exact day I broke out in a spot and over the months I noticed some patterns emerging – such as breaking out the exact day I ovulated or exactly 5 days before my period.
UPDATE August 2016: Shortly after I updated this post in April I started having acupuncture treatment. I’m still tracking my cycles as my acupuncturist finds it a useful tool to understand my body better but I noticed my temperature has completely gone crazy since I started acupuncture. My charts had finally started to resemble something similar to the graph above, although my BBT in the 2nd half of my cycle would plummet down quite low every few days indicating an issue with progesterone levels. As soon as my acupuncture started my BBT started going up and down, up and down throughout the month and my app wasn’t able to recognise a spike mid-cycle. I’m not too concerned by this as acupuncture has been really helpful with regulating my cycles and getting rid of ovulation pain completely. I’m looking forward to seeing what the next few months brings and I’ll keep you updated if and when my progesterone levels begin to increase and my temperature starts to balance out again.
UPDATE April 2017: Ok so it’s been a while since I updated but to be truthful there wasn’t a huge amount to say. Since last August my BBT has been up and down with no consistent pattern and my periods have been pretty wild the last few months too. However, after getting my copper IUD removed and hair mineral analysis done at the beginning of the year and learning some shocking truths about what was going on in my body, I decided to completely overhaul my diet and switch up my supplement regime. The results? Within one month my BBT chart when from crazy to calm and it even recognised ovulation! I could believe it! Below are my charts from one month to the next but literally just changing my diet! There’s still some way to go but the huge improvement I’ve seen in just 29 days (after a year and a half of tracking) is enough for me to keep going with my new diet and supplement plan.
decoding your basal body temperature chart
From looking at our monthly charts we are able to see at a glance, the length of our menstrual cycle, when we ovulate, the length of our two phases and whether our cycles are regular or irregular. However, by digging a little deeper, we’re able to discover more about our hormones and how they may be affecting our health and wellbeing!
basal body temperature troubleshooting
During my research I came across some great information from White Lotus Clinic – these troubleshooting points may provide valuable information to help you discover the root cause of your hormonal imbalances.
my follicular phase is too long/ is too short/ too high or too low
If the first 2 weeks of your cycle is too long/short/high in temp/low in temp it can indicate hormonal imbalances caused by thyroid conditions or emotional stress. For example, emotional stress and thyroid disorders can show up as irregular high, then low, then high temperatures from day to day. This instability of temperature can see an increase in the length of the follicular phase – this is why stress = late periods!
In Polycystic Ovarian Syndrome the follicular phase can be longer than the typical 14 days, indicating insulin resistance or excess androgens (male hormones). If your ‘ovulation spike’ happens after day 14 this could signal that your follicular phase is longer and you may want to work on bringing down any excess androgens . Nutritional deficiencies and a decrease in blood circulation to the uterus can also cause this phase to be abnormally long.
Do bear in mind that everyones cycles are different so there isn’t one perfect rule for everyone. However, if you’re feeling hormonally unbalances or suffering from missing periods, PMS, acne or other symptoms then it’s worth decoding your cycle to help you get to the root cause of your issues.
my temperature seems to be quite low
Basal temperatures and thus progesterone levels should remain elevated for fourteen days after ovulation. Progesterone levels peak during the middle of the luteal phase, about a week after ovulation, but if your temperature regularly drops below 36.50C during the second half of your cycle, it could indicate low progesterone levels.
If your temperature is regularly below 36.2C during your period then you may have poor thyroid function and may need to look into boosting your thyroid.
my temperature creeps up slowly at ovulation
If your temperature slowly creeps up halfway during your cycle instead of having an instant spike then this can also signal low progesterone levels.
my cycles are too long
Longer cycles can be an indication of low hormone levels in general or PCOS, which is characterised by excess testosterone. Long cycles can also be due to acute stress, but generally stress induced long cycles will be more of a one-off than a recurring theme each month.
charting basal body temperature for balancing hormones + clearer skin
All you need to start charting is:
- A digital 2 decimal place thermometer. They’re easy to get and cheap! This is the one I got off Amazon but you can probably pick one up from any pharmacy – just make sure it reads 2 decimal places!
- A BBT chart or Fertility/Period Tracker App. You can download BBT charts off the internet for free but I find logging my BBT on my phone first thing in the morning much easier – no need to hunt for a pen! Again, you will need to find an app that allows you to log your temperature to 2 decimal places. I used to use the free app Clue – but then I had my copper coil removed so wanted something that specifically designed to be an effective contraceptive tool so I now use Natural Cycles and LOVE IT – you can read more about how it compares to the pill, IUD and condoms here! You can get a 30 day free trial by signing up on their website and save 10% on the yearly package when you shop via this link here.
Happy Charting! Let me know your thoughts on basal body temperature in the comments below. Have you discovered any interesting patterns to your cycle through BBT charting?
Peace, Love & Clear Skin,