“Is there a risk of bleeding on keto?”


Is it possible to start bleeding even if you’re in menopause if you start a ketogenic diet? What could a sudden heavy bleeding be about? And what is the ultimate protein to fat ratio?

Get the answer to these questions in this week’s Q&A with fertility specialist Dr. Fox:


I have noticed women talking about bleeding on this diet, is this something I should be concerned about will or can this happen to me even though I no longer have periods?


Dr. Fox:

Good question: Theoretically, what will happen with cycling is that people who are irregular will become more regular and hormone levels may rise closer to normal in those who are suppressed from bad metabolism. Some may notice more painful cycles as a result of increased estrogen, but the estrogen is again moving toward normal, not becoming excessive. Remember low estrogen results in worse metabolic function. There is no explanation for “random bleeding” with the diet.” Every indication is that menstrual function would be approaching normal for a female. Bleeding can happen for many reasons, I would never “blame” ketotic nutrition for this.

Sudden heavy menstrual bleeding

Hi Dr. Fox

I am on my third week of LCHF and I am loving it. I have PCOS and all of sudden I began heavy menstrual bleeding. I usually have 40-45 day light to moderate periods. I do not take BCP’s only metformin 1500mg and Spironolactone 200mg and lisinopril 5mg and a MVI. Why all of sudden like this? Is this like an indicator of changing hormones? Last period was just 2 weeks ago.


Dr. Fox:

Impossible to say exactly. Could be hormonal change or could just be a sporadic abnormality in your cycle. People with 40-45 day cycles often will have such aberrations.

Help with the Protein to Fat ratio?

I am 65 yrs old and my doctor recommended a Low carb high Fat diet. How much protein, Fat, Carb and Sugar should I ingest each day? every time I look for the answer I get a different one. Thank you


Dr. Fox:

Great Question: protein should be 1.2-1.7 g/kg of ideal body weight. For 150 lbs it is about 70 – 100 gms protein per day. Not as much as you might think. No sugar, that one is easy. Shoot for about 20 grams per day exclusively from vegetables. As long as you are not severely insulin resistant (BMI >35 or so), you can tolerate unlimited non-starchy vegetables. Fat should be about 70-90% of calories, again depending on the severity of your problem. The caution I give everyone is to not pick “processed foods” and count carbs. Eat fresh fats, protein sources and vegetables and you don’t have to think about it much at all. The stress of counting these things is difficult. Using my fitness pal for a month or so to get %’s for macronutrients is good education, but once learned roughly, forget about the figuring and just eat. You will learn what works and what doesn’t by the way your gut (bloating) responds and your weight. Also weigh once per week or so. not every day.

More questions and answers

Questions and answers about low carb

Read all earlier questions and answers to Dr. Fox – and ask your own! – here:

Ask Dr. Fox about nutrition, low carb and fertility – for members (free trial available)

Videos with Dr. Fox



How to reverse PCOS with low carb


  1. Jan
    I had sudden heavy bleeding that lasted for 8 weeks when I first started Keto. My doctor shrugged his shoulders and said it was “just menopause”. But the bleeding was approaching hemorrhages I had with placenta prévia during pregnancy and I got scared. I went to Dr. Google and found that flax is a phytoestrogen which can cause bleeding. BINGO! I was eating a flax “muffin” daily to replace bread. Within 48 hours of my last muffin, the bleeding stopped. I was anemic by then. Don’t underestimate plant hormones!
  2. Vanessa
    I am 27 and I have PCOS and when I started taking the keto pill my period came the next day and it start fr a very ⁷long while I haven't been bleeding fr months so the keto bring back my period was a good thing but the time it stay was over bearing


  3. jane
    thank you, jan, for posting your reply. i'm just in menopause and have embarked on a regime of extreme nutrition days (literally meal planning using cronometer -- highly recommend!) cycling with fasting days. and, of course, i've been adding ground flax into my diet to make sure my omega ratios are optimal every day! sure enough, after two weeks, i've had a bit of spotting. now that i know what to look for, i'll probably find lots of information. of course, i'll check with my dr. as well. still, yours was the first information i found that explained what was happening and i'm greatly relieved. thank you again for posting your experience, it helped me!
  4. Tina
    I know this is old but I too have awful heavy periods/breakthrough bleeding on keto (even though I take birth control that's supposed to suppress my period) but ironically I don't think it's the keto. I think it's the rapid weight loss that always comes with it for me because if I go over carbs it doesn't happen. That's honestly how I can tell if I'm doing it right as I have really bad (almost need to stay home bad) periods once the weight starts falling off. I read it's something about estrogen that's stored in fat cells being released..idk

    I'd be curious to know if there's anyone on keto at a normal, healthy weight, not trying for weightloss who has this happen as it's hard to tell if it's estrogen being released from fat cells or just something else about low carb plans since I do have a lot of weight left to lose.

    Reply: #5
  5. Jay
    I also have this same thing happen to me as well…it seems that when I fast or my carbs are lower for the day, my bleeding gets worse. I would love to know others thoughts on it as well.

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