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What Does CFU Mean in Probiotics?
What does CFU mean in probiotics? It stands for colony-forming units, a count of live microbes able to multiply. NIH advises looking for a CFU count stated through the end of shelf life. The FemiCore bottle prints a 50 mg probiotic blend and no CFU number, so the live-cell count is unknown.
Written by the FemiCore label benchUpdated · 4 min read
The term
What does CFU stand for on a probiotic label?
CFU stands for colony-forming units. It counts the live microbes in a dose that are able to divide and form a colony when grown in a lab dish.
The idea is simple. Picture spreading a drop of liquid on a dish. Each living cell, or small clump, grows into a visible dot. Count the dots and you have the CFU.
Dead cells never make a dot. That is why CFU says something a weight in milligrams cannot: how much of the product was alive when it was tested.
A CFU number is usually written in millions or billions, such as 5 billion. A label should also say when the count applies.
Why it matters
Why does the CFU count matter for a probiotic?
The CFU count matters because probiotics must be alive to work as the term is meant. NIH notes that label weight includes dead cells and advises looking for a CFU count at the end of shelf life (NIH ODS, Probiotics).
The same fact sheet says effects are strain-specific, so a result for one strain does not carry over to another (NCCIH, Probiotics). A good label therefore names the strain and the count.
| Label item | Why it helps | FemiCore label |
|---|---|---|
| Strain code | Links to trials | Printed for all five |
| CFU count | Measures live cells | Not printed |
| "At expiration" wording | Counts survivors, not the day of filling | Not printed |
| Storage advice | Protects the cells | Cool, dry place |
Strain codes are a real plus here. The strains page lists all five.
GenusLactobacillus
Speciescrispatus
Strain codeLCr86
A probiotic's effect belongs to the strain, the code after the species name, not to the species in general (NCCIH, Probiotics) (NIH ODS, Probiotics). Two strains of one species can behave differently, so research on "L. crispatus" in general does not transfer to LCr86.
| Strain on the label | Place | Most per capsule | Strain-level research we found | Caution |
|---|---|---|---|---|
| Lactobacillus crispatus LCr86 | 1 of 5 | at most 50 mg | One registered trial gave 10 billion CFU a day orally (vaginal outcome) | Ask first if your immune system is weakened. |
| Lactobacillus acidophilus LA88 | 2 of 5 | at most 25 mg | No published trial found for this strain code | Ask first if your immune system is weakened. |
| Lactobacillus plantarum N13 | 3 of 5 | at most 16.7 mg | No published trial found for this strain code | Ask first if your immune system is weakened. |
| Lactobacillus gasseri LG08 | 4 of 5 | at most 12.5 mg | No published trial found for this strain code | Ask first if your immune system is weakened. |
| Lactobacillus casei LC16 | 5 of 5 | at most 10 mg | No published trial found for this strain code | Ask first if your immune system is weakened. |
Searched October 2026. LCr86 has one completed placebo trial (80 women, 10 billion CFU a day by mouth, 8 weeks, vaginal Nugent score) with no results posted (ClinicalTrials.gov NCT06830122, LCr86). "Lactobacillus" species were renamed in 2020 (for example L. casei is now Lacticaseibacillus casei); labels often keep the old names.
This bottle
Does the FemiCore label give a CFU number?
No, the FemiCore label gives no CFU number. It prints a Probiotic Blend of 50 mg and lists five strains in order: L. crispatus LCr86, L. acidophilus LA88, L. plantarum N13, L. gasseri LG08 and L. casei LC16.
Under blend rules, the strains are listed from most to least by weight and only the total is shown (21 CFR 101.36, supplement labeling). So the first strain weighs at most 50 mg, the second at most 25 mg, and the fifth at most 10 mg. Those are ceilings, not amounts.
Weight, even if known, would still not tell you how many cells were alive. Without a CFU figure, the dose of live bacteria in one capsule is unknown.
One completed industry trial of LCr86 used 10 billion CFU a day by mouth, but no results were posted, and the FemiCore label cannot be matched to that dose (ClinicalTrials.gov NCT06830122, LCr86).
FemiCore: from $49 a bottle30 capsules · 2, 3 or 6 bottles · free shipping on 6 · 60-day money-back guarantee
See packsShelf life
Do probiotic counts fall over time?
Live counts can fall as a product ages, which is why the end of shelf life is the useful moment to measure. A number taken on filling day can overstate what you swallow months later.
NIH adds that products must be alive to work and some need refrigeration, so follow the storage line on the bottle (NIH ODS, Probiotics). The FemiCore bottle says to keep it in a cool, dry place and does not call for the fridge.
Keep the cap tight, away from a hot window or a car glovebox, and use the bottle within its date. Those habits protect any live cells that are there, though they cannot add a count that was never measured.
What to do
What should you ask a seller about CFU?
Ask for the CFU per capsule, stated at the end of shelf life, with the strain it applies to. A seller who tests will have the number.
Ask also how the capsules are stored and whether a lot report exists. No lab report is published for this product.
If you have a weak immune system or a serious illness, speak to a clinician first. Probiotic risks are higher in those groups (NCCIH, Probiotics).
The sales page lists $79 a bottle on two, $69 on three and $49 on six. Each bottle holds 30 capsules, enough for 30 days.
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FAQ
CFU questions, answered
Is a higher CFU number always better?
No. Effects depend on the strain, not only the count, and no source we cite names a best number. A count is useful mainly to show live cells reached the end of shelf life.
Is CFU the same as billion on a label?
Billion is the size of the count. A label saying 10 billion CFU means ten billion colony-forming units. The word CFU tells you the cells were counted alive.
Can I work out the CFU from the milligrams?
No. Milligrams include dead cells and carriers, so the two figures do not convert. Only a lab count on live cells gives CFU.
Do dead probiotic cells still count in a CFU figure?
No. CFU counts only cells able to grow into a colony. Dead cells add to the weight in milligrams but never to the CFU, which is the main reason the two numbers differ.
Where should the CFU appear on the box?
Usually in the Supplement Facts panel beside the strain names, ideally with the words through the end of shelf life. If it is absent, the label has not given the figure.
Who wrote this
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, FTC, EMA and peer-reviewed sources.
Last updated . See our editorial standards and how we check reviews. This website is run by a U.S. stocking partner for FemiCore, not by the manufacturer or the label's distributor. We are paid when you buy through our order links.
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More about FemiCore
U.S. stocking partner for FemiCore
Ready to try FemiCore?
Start with a check of your medicines, then pick a pack. Six bottles ship free and cost the least per bottle, and every pack sits inside the 60-day money-back window.
- Secure checkout
- 60-day money-back guarantee
- Ships from the U.S.