Reduce Blood Sugar by using Apple Cider Vinegar

by Tammy Gilden
(Toronto Ontario Canada)

Apple Cider Vinegar Blood Sugar Reduction

Apple Cider Vinegar Blood Sugar Reduction



Question from Tammy Gilden:


I developed type 2 diabetes and take metformin. I have improved my diet, but my waking blood sugar is still often 8–10 mmol/L, and my doctor has discussed insulin.


I am interested in apple cider vinegar. What dose should be used in teaspoons or tablespoons? Should I take a vinegar-free week? Can it be mixed with apple juice or grape juice?


I also want to ask about rambutan: how many should I eat to make blood sugar changes?




Quick Answer


Apple cider vinegar may have a small effect on blood sugar in some people, but it does not cure diabetes and should not replace metformin, insulin, food planning, exercise, or medical care.


If your doctor says it is safe, a cautious way is 1 teaspoon to 1 tablespoon diluted in a large glass of water, taken with food or shortly before a meal. Do not drink it straight, and do not mix it with apple juice or grape juice because juice can raise blood sugar.


Rambutan should be treated as a fruit, not as diabetes medicine. There is no proven number of rambutans that reliably lowers blood sugar.



Answer by Dr. Albana Greca, MD, MMedSc


Hi Tammy,


Thank you for sharing your story. I understand your wish to avoid insulin, but needing insulin is not a personal failure. Type 2 diabetes can progress over time, and sometimes insulin is the safest way to protect the eyes, kidneys, nerves, heart, and blood vessels.


Your Morning Blood Sugar Needs Review


A waking blood sugar of 8–10 mmol/L is about 144–180 mg/dL. This is higher than the usual fasting target for many adults with diabetes.


Morning highs can happen because of the dawn phenomenon, fatty liver, insulin resistance, late evening carbohydrates, poor sleep, stress, illness, or not enough medication effect overnight.


You may find this useful: why blood sugar is high in the morning.


How to Take Apple Cider Vinegar More Safely


If your doctor agrees, start small. Do not take apple cider vinegar undiluted.



  • Start with 1 teaspoon in a large glass of water.

  • If tolerated, some people use up to 1 tablespoon diluted in water.

  • Take it with food or shortly before a meal.

  • Rinse your mouth with plain water afterward to protect tooth enamel.

  • Stop if you get throat burning, stomach pain, nausea, reflux, or low blood sugar symptoms.


I do not recommend mixing it with apple juice, grape juice, orange juice, or honey. These can add sugar and may raise blood glucose.


Do You Need a Vinegar-Free Week?


There is no proven medical rule that everyone needs a “vinegar-free week.” The more important point is safety: avoid long-term daily use without discussing it with your doctor, especially if you have kidney problems, low potassium, reflux, gastroparesis, osteoporosis risk, or take insulin, diuretics, digoxin, or other medicines.


Read more here: diabetes and supplements.


Apple Cider Vinegar and Metformin


Metformin alone usually has a low risk of low blood sugar, but low blood sugar risk can increase if vinegar is combined with insulin, sulfonylureas, fasting, skipped meals, or multiple glucose-lowering supplements.


If your doctor is considering insulin, do not delay treatment only because of vinegar. Insulin may be temporary or long-term depending on your glucose pattern and HbA1c.


What About Rambutan?


Rambutan is a sweet tropical fruit. The edible flesh contains natural sugar, so it may raise blood glucose depending on portion size.


Some research has studied compounds such as geraniin from rambutan peel or rind extracts, but this is not the same as eating rambutan fruit. There is no proven number of rambutans that safely lowers blood sugar.


Do not use rambutan seeds or homemade seed remedies for diabetes. Safety is uncertain, and they are not a proven treatment.


Helpful page: choosing fruits for diabetics.


What I Would Focus On First



  • Check fasting and bedtime glucose for 1–2 weeks.

  • Record dinner timing, carbohydrates, sleep, stress, and activity.

  • Ask your doctor for your latest HbA1c, kidney function, liver markers, and urine albumin test.

  • Discuss whether insulin, a GLP-1 medicine, or an SGLT2 inhibitor is appropriate for you.

  • Do not combine several herbs, Tibetan products, vinegar, or fruit extracts without medical review.



Important Safety Note


Apple cider vinegar, rambutan, herbs, and supplements should not replace diabetes medication. Seek urgent help for vomiting, dehydration, confusion, severe weakness, fast or deep breathing, fruity-smelling breath, chest pain, or very high blood sugar with ketones.




Doctor’s Note


Tammy, your morning readings are high enough to deserve a treatment review. Vinegar may be used cautiously as a food ingredient, but it is not a substitute for proper diabetes care. If your doctor recommends insulin, discuss your concerns openly rather than refusing it because of fear.




Educational safety note: This answer is for general diabetes education only. It does not replace personal medical advice, diagnosis, or treatment. Do not start, stop, or combine diabetes medication, insulin, vinegar, herbs, fruit extracts, or supplements without speaking with your healthcare provider.



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