What Every Cyster Needs To Know About Metformin

What Every Cyster Needs To Know About Metformin (Pinterest)

Metformin is touted as the “magic bullet therapy for PCOS” because it helps women with PCOS with, “…weight loss, improve insulin resistance, restore normal ovulatory cycles, increase fertility, decrease hyperandrogenism, decrease the rate of spontaneous abortions, and decrease the risk of gestational diabetes.” Sounds great, right? Of course it does, but that doesn’t mean you should go ahead and fill that metformin prescription without knowing all the risks and benefits. Don’t worry, I provided the information you’ll need to begin your metformin research; so let’s begin!


For one, metformin depletes the body of B12.

Why Is B12 Important to The Human Body?

According to “The Vitamin B12 Connection”:

Vitamin B12 is necessary for the proper functioning of many of the most basic systems in the body. It is crucial for sustaining physical, emotional and mental energy. B12 is essential for female reproductive health and pregnancy. It affects everything from cell formation to circulation to moods.


B12 Facts:

  • As stated in Diabetes in Control:
    • B12 is frequently misdiagnosed as diabetic neuropathy (damaged nerves caused by diabetes).
    • An individual can be deficient in B12 without symptoms of anemia or peripheral neuropathy (damaged peripheral nerves).
    • B12 deficiency caused by Metformin is “poorly recognized” and “not screened for or treated prophylactically” (or preventively) by the most doctors.
  • Most people deficient in B12 eat plenty of foods containing B12; however, people become deficient in B12 due to the inability to absorb or effectively make use of vitamin B12.
  • If B12 deficiency is left untreated, it can cause megaloblastic anemia, fatigue, constipation, poor memory , weight reduction, dementia, neurological changes such as numbness and tingling in the hands and feet, trouble upholding balance, depression, weakness, confusion, loss of appetite, and mouth or tongue soreness.


Metformin Induced B12 Deficiency Facts:

  • 30% of metformin users are deficient in B12.
  • Metformin induced B12 deficiency can be prevented with annual B12 level check-ups and B12 supplements.
  • Calcium supplements can reverse the effects of metformin induced B12 deficiency.
  • Individual’s risk of B12 deficiency are higher in individuals taking high dosage of metformin for more than 3 years.


More Metformin Facts:

  • A systematic review of oral contraceptives and metformin was conducted to evaluate the effectiveness for adolescent PCOS treatments. Researchers concluded:

Current evidence is derived from very low to low quality evidence. Therefore, treatment choice should be guided by patient values and preferences while balancing potential side effects. Future high quality RCTs [randomized control trials] are needed to address several questions for the treatment of adolescents with PCOS.


Overlooked Common Side Effects of Metformin:

  • Abdominal pain
  • Nose, Throat, and Sinus Infection
  • Constipation
  • Distended abdomen
  • Diarrhea
  • Dyspepsia/heartburn
  • Taste disturbance
  • Flatulence
  • Headache

Common side effects of any medication are usually dismissed as minor. But are common side effects really trivial? Of course not; pain is a sign that something is wrong and it’s never fun to experience. Why else would pharmaceutical companies and healthcare system exist? However, this doesn’t mean you shouldn’t take metformin because it causes unpleasant side effects; instead, be mindful about what you are signing up for. Are you 100 % okay with experiencing diarrhea, headaches, heartburn or stomach pain for a few days or weeks for benefits you aren’t guaranteed reap? Are there other ways to lose weight, increase fertility or improve insulin resistance without risky or annoying side effects? Don’t worry, there are no right or wrong answers—only what you are willing to endure to treat your PCOS. For some women, the benefits outweigh the cons and for others, it didn’t. Below are women with PCOS sharing their metformin story.


Candid Metformin Reviews:


Nonetheless, before you decide whether metformin is best for you, consider Hany Lahen review about the, “Role of metformin in the management of polycystic ovary syndrome”:

The use of metformin in PCOS has received a lot of attention for obvious reasons. Once thought of as a wonder drug, the accumulating evidence on the efficacy of metformin has been disappointing. The lack of an emphatic or overwhelming efficacy is largely due to the patients’ variability in phenotypes and their metabolic parameters. Some studies have tried to identify the patients that are most likely to benefit from metformin, yet again the results have not been forthcoming. Consequently the burden falls back on the clinician who should be familiar with the gist of the available evidence to be able to identify the right patient for the treatment in hand. Obtaining an evidence of IR is a good starting point prior to recommending its use.

Based on the available evidence, however, metformin does not replace the need for lifestyle modification among obese and overweight PCOS women. The evidence categorically does not encourage its use to help weight loss either although it may be useful in redistributing adiposity according to some evidence. It takes a longer time to help with ovulation induction hence it fared worse than clomiphene citrate in the head-to-head studies, however, as a long-term treatment, metformin supplemented with lifestyle changes may prove superior. Its benefit in IVF patients is only confirmed with regard to reduction of the incidence of OHSS which is important given its high risk among PCOS patients. As for its usefulness in pregnancy, the jury are still out regarding its role in reducing the risk of miscarriage; however, the available evidence regarding GDM prevention is encouraging.

The long-term use of metformin to prevent remote complications of PCOS is uncertain and a significant amount of work is needed before a decision can be made on this front. Stipulations from studies carried out on the general population is not the same and can be misleading given the diversity of PCOS patients with regard to their metabolic comorbidities.

Key Words:

  • Ovarian hyperstimulation syndrome (OHSS)
  • Gestational diabetes mellitus (GDM)
  • Insulin resistance (IR)


Hopefully, this post has inspired you to delve deeper into your metformin research and help you come to a decision about whether metformin is best to treat your PCOS. Remember, there are no right or wrong answers—there is only what you are willing to endure to manage your PCOS.


Thanks for reading !


Subscribe To Learn About:

Nutrition + Fitness + Women’s Health + Other Healthy Living Tips !

It’s One Of The Easiest And Best Steps You’ll Make On Your Healthy Lifestyle Journey.
* indicates required



Share This Awesome Post With Your Friends:

What Every Cyster Needs To Know About Metformin (Pinterest) What Every Cyster Needs To Know About Metformin (Facebook)

What Every Cyster Needs To Know About Metformin (Twitter)



  1. Zisser, Howard Craig. “Polycystic Ovary Syndrome and Pregnancy: Is Metformin the Magic Bullet?” Diabetes Spectrum20.2 (2007): 85–89. Web. 22 June 2016.
  2. Judy McBride. “B12 Deficiency May Be More Widespread Than Thought.” Ars.usda.gov. N.p., 2 Aug. 2000. Web. 12 June 2016.
  3. Al Khalifah, Reem A. et al. “Metformin or Oral Contraceptives for Adolescents With Polycystic Ovarian Syndrome: A Meta-Analysis.”Pediatrics137.5 (2016): n. pag. Web.
  4. Bauman, W. A. et al. “Increased Intake of Calcium Reverses Vitamin B12 Malabsorption Induced by Metformin.” Diabetes Care23.9 (2000): 1227–1231. Web. 12 June 2016.
  5. Carlsen, Sven M., Marit P. Martinussen, and Eszter Vanky. “Metformin’s Effect on First-Year Weight Gain: A Follow-up Study.” Pediatrics130.5 (2012): e1222–e1226. Web. 12 June 2016.
  6. “Common and Rare Side Effects for Metformin Oral.” WebMD. N.p., n.d. Web. 12 June 2016.
  7. Control, Diabetes In. “Metformin-Induced Vitamin B12 Deficiency Presenting as a Peripheral Neuropathy.” Diabetes In Control. A free weekly diabetes newsletter for Medical Professionals.N.p., 30 Apr. 2010. Web. 12 June 2016.
  8. “Hair Loss Newsletter.” Women’s International Pharmacy. N.p., n.d. Web. 12 June 2016.
  9. Hashim, Hatem Abu. “Twenty Years of Ovulation Induction with Metformin for PCOS; What Is the Best Available Evidence?”Reproductive BioMedicine Online32.1 (2016): 44–53. Web. 12 June 2016.
  10. “Homocysteine and Heart Disease.” WebMD. N.p., n.d. Web. 12 June 2016.
  11. Knowler, William C. et al. “Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin.” The New England Journal of Medicine346.6 (2002): 393–403. Web.
  12. Lashen, Hany. “Role of Metformin in the Management of Polycystic Ovary Syndrome.” Therapeutic Advances in Endocrinology and Metabolism1.3 (2010): 117–128. Web. 12 June 2016.
  13. Legro, Richard S. “Metformin during Pregnancy in Polycystic Ovary Syndrome: Another Vitamin Bites the Dust.” The Journal of Clinical Endocrinology and Metabolism95.12 (2010): 5199–5202. Web. 12 June 2016.
  14. Meng, Yuming et al. “Association between High Serum Homocysteine Levels and Biochemical Characteristics in Women with Polycystic Ovarian Syndrome: A Systematic Review and Meta-Analysis.” PloS One11.6 (2016): e0157389. Web.
  15. “Office of Dietary Supplements – Dietary Supplement Fact Sheet: Vitamin B12.” N.p., n.d. Web. 12 June 2016.
  16. Salomäki, Henriikka et al. “Prenatal Metformin Exposure in Mice Programs the Metabolic Phenotype of the Offspring during a High Fat Diet at Adulthood.” PloS One8.2 (2013): e56594. Web.
  17. Tartarin, P. et al. “Metformin Exposure Affects Human and Mouse Fetal Testicular Cells.” Human Reproduction27.11 (2012): 3304–3314. Web. 12 June 2016.
  18. Ting R et al. “RIsk Factors of Vitamin b12 Deficiency in Patients Receiving Metformin.” Archives of Internal Medicine166.18 (2006): 1975–1979. Web. 12 June 2016.
  19. Tomkin, Gerald H. “Malabsorption of Vitamin B12 in Diabetic Patients Treated with Phenformin: A Comparison with Metformin.” British Medical Journal3.5882 (1973): 673–675. Web. 12 June 2016.
  20. Wessels, Bart et al. “Metformin Impairs Mitochondrial Function in Skeletal Muscle of Both Lean and Diabetic Rats in a Dose-Dependent Manner.” PLOS ONE9.6 (2014): e100525. Web. 12 June 2016.
  21. Wulffelé, M. G. et al. “Effects of Short-Term Treatment with Metformin on Serum Concentrations of Homocysteine, Folate and Vitamin B12 in Type 2 Diabetes Mellitus: A Randomized, Placebo-Controlled Trial.” Journal of Internal Medicine254.5 (2003): 455–463. Web. 12 June 2016.
  22. Zisser, Howard Craig. “Polycystic Ovary Syndrome and Pregnancy: Is Metformin the Magic Bullet?” Diabetes Spectrum20.2 (2007): 85–89. Web. 12 June 2016.
  1. Wulffelé, M. G. et al. “Effects of Short-Term Treatment with Metformin on Serum Concentrations of Homocysteine, Folate and Vitamin B12 in Type 2 Diabetes Mellitus: A Randomized, Placebo-Controlled Trial.” Journal of Internal Medicine254.5 (2003): 455–463. Web. 17 Dec. 2015.



Continue Reading