Taking Benadryl With Culturelle

In our latest question and answer, the pharmacist discusses whether or not there is a drug interaction between Benadryl and Culturelle.

May 22, 2018

Jalen asked

Is it safe to take Culturelle and Benadryl together?


Culturelle does not interact with Benadryl and they are considered safe to take together. It is very unlikely that taking Culturelle with Benadryl will result in any increased side effects compared to taking either medication by itself.

Culturelle doesn’t usually cause side effects other than some mild bloating and gas. Benadryl has the common side effects of drowsiness, dry mouth, constipation, and dizziness.


Culturelle is a brand of probiotic products that includes various formulations for adults, specifically women, kids, and babies. All the products contain the same bacteria, lactobacillus rhamnosus GG. In general, probiotics are thought to work by providing “good” bacteria that will live in the gut and keep “bad” or disease-causing bacteria from causing problems in the gut.

Lactobacillus rhamnosus GG is the most well-studied lactobacillus strain and some studies have shown it to be likely effective for helping to resolve diarrhea in children caused by the rotavirus. Studies for other health conditions like constipation and diarrhea in adults have had mixed results with some studies showing benefit and some showing no benefit from taking probiotics.

The dose of Culturelle varies by product, so it is best to follow the package directions. They are classified as dietary supplements and are not strictly regulated by the FDA which means their effectiveness, safety, purity, and potency is not guaranteed. Some products contain lactose or milk protein, so use caution if you have these or other food allergies. It is considered generally safe to take probiotics and they are not known to have any serious interactions with other drugs including the antihistamine, Benadryl.


Benadryl (diphenhydramine) is a first generation antihistamine, which are noted for their relatively short duration of action (~4 to 8 hours) and their sedating properties. In addition to its use for treating seasonal allergy symptoms such as a runny nose, Benadryl is also effective for treating symptoms of nausea, vomiting, and vertigo associated with motion sickness.

As Benadryl has fairly significant sedating effects, it is often used as a night time sleep aide and is common component of over the counter sleep products such as ZzzQuil. Benadryl begins to work about 20 to 30 minutes after taking by mouth and maximum blood concentrations are reached after 1 to 2 hours.

The duration of action varies by individual but generally lasts 4 to 6 hours. Benadryl is generally well tolerated but can cause the following side effects:

  • Sedation
  • Dizziness
  • Respiratory depression (rare)

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