Home › FemiCore Side Effects
By QuocNguyen, Biochemist · Reviewed by QuocNguyen · Updated October 8, 2026
Is FemiCore safe? For most healthy women, the side effects are mild and short-lived. But two of its nine ingredients, uva ursi and berberine, need more care than the sales page suggests. Here's an ingredient-by-ingredient look at what can happen and when to stop.

The side effects people most often notice with FemiCore come from the probiotic strains, not the herbs. When new bacteria arrive in the gut, digestion can take a little time to adjust. In the first one to two weeks, some women notice:
These effects usually fade on their own as the gut settles. Taking FemiCore with breakfast, as the manufacturer recommends, can help. If digestive symptoms are still bothering you after two weeks, or they're getting worse rather than better, stop taking it and talk to your doctor.
Cranberry extract can occasionally cause mild stomach upset as well, though this is more common with large amounts of juice than with capsules.
Uva ursi (bearberry) leaf contains arbutin, which the body converts to hydroquinone. Hydroquinone is what gives uva ursi its antimicrobial effect in the urine, but it is also the reason regulators limit how long it should be used.
The European Medicines Agency's herbal monograph recommends using uva ursi for no more than about one week at a time and no more than five times a year. It is not recommended for children, during pregnancy or breastfeeding, or for people with kidney disease. Possible side effects include nausea, vomiting and stomach upset, and it can turn urine a greenish-brown color, which is harmless.
This creates a real tension with how FemiCore is marketed. The manufacturer suggests taking it daily for three to six months. The amount of uva ursi in each capsule matters a great deal here, so check the Supplement Facts label and show it to your pharmacist before planning long-term use.
Berberine is a plant compound with antibacterial effects. It is generally well tolerated in the short term, though some people get constipation, diarrhea, gas or stomach cramps.
The bigger issue is how it interacts with other things in the body. Berberine can lower blood sugar, so combined with diabetes medication it may push blood sugar too low. It also affects liver enzymes, including CYP3A4 and CYP2D6, that break down many common drugs. That can raise or lower the levels of those medications in your blood.
Talk to your doctor or pharmacist before taking FemiCore if you take:
Berberine should be avoided during pregnancy and breastfeeding, as it may harm a developing baby or newborn.
Lactobacillus probiotics have a long record of safe use in healthy adults. The rare serious problems reported, such as bloodstream infections, have occurred mainly in people who are very ill, have a weakened immune system, or have a central venous catheter. If any of these apply to you, only take probiotics under medical supervision.
If you have a history of small intestinal bacterial overgrowth (SIBO) or a sensitive gut, start FemiCore at a time when you can watch how your body responds.
| Situation | Why it matters |
|---|---|
| Pregnant or breastfeeding | Uva ursi and berberine are not advised |
| Under 18 | Uva ursi is not recommended for children |
| Kidney or liver disease | Uva ursi and berberine may add strain |
| Diabetes or blood pressure medication | Berberine can lower blood sugar and interact with drugs |
| Blood thinners | Berberine and large amounts of cranberry may affect warfarin |
| Weakened immune system | Small risk of infection from probiotics |
| Active UTI symptoms | Needs medical treatment, not a supplement |
Stop taking FemiCore and contact a doctor if you notice:
A few simple steps make it much less likely you'll run into problems:
For how to take FemiCore day to day, see our dosage and usage guide.
Most women have no side effects or only mild bloating and gas in the first week or two. Uva ursi and berberine carry additional cautions, including drug interactions and limits on long-term use.
Lactobacillus probiotics are not known to cause yeast infections, and a healthy Lactobacillus balance is generally protective. If you develop itching or unusual discharge, see a doctor to find the cause.
The probiotic strains are generally safe long term. Uva ursi is usually advised for short courses only, so check the amount per capsule with your pharmacist before taking FemiCore for months.
Ask your doctor first. Berberine can lower blood sugar and may add to the effect of metformin and other diabetes medications.
Uva ursi can turn urine greenish-brown, which is harmless. If you see red or pink urine, or have pain, contact a doctor.