Frontline Plus are manufactured by Merial, France, including that of Merial, USA. Frontline Plus are imported by different Merial branches and distributors all over the world, including USA. Packagings vary according to rules and regulations of individual country.

EPA never states that expiration dates on Frontline Plus Products are indications of counterfeits. A lot of counterfeit products do not carry expiration dates now. According to EPA, USA is the only country which does not require an expiration date printed on pesticides. The reason: Under the normal climate, pesticides generally last at least 3 years. The normal reasonable consumer is expected to use up the pesticides within 2 years. EPA provides the following guidelines to differentiate between real and fake Frontline Plus products. 

The guidelines are provided below:

The pesticide products are sold in a carton. It is difficult to distinguish counterfeit products from EPA-registered  or authentic Frontline Plus products because they look very much alike. To determine if the product you have purchased is legitimate, check to see if it meets the following criteria. If the product fails any one of these criteria, it most likely is an illegitimate product and should be disposed of properly.

Frontline products

1. The lot number on the retail carton matches the lot number on the applicator package and/or the individual applicators.  (Most important characteristic that differentiate fake and real Frontline Plus)

2. The instruction leaflet is included. It provides the following information: first-aid statements, including emergency U.S. telephone numbers; precautionary statements for humans and pets; directions for use; and storage and disposal statements.
3. The pesticide is contained in an applicator package, which is child-resistant. The directions for opening the child- resistant applicator package include an illustration that actually looks like the applicator package. The directions include "To remove applicator, use scissors or lift and remove plastic tab to expose foil, then pull down."
4. Text on the package is in English only.  
5. Once you open the applicator package, each individual applicator has a label that includes the registrant's name "Merial;" the product name; the EPA registration number; percentage (%) of active ingredient(s) (fipronil for Frontline Top Spot products; and fipronil and (S)-methoprene for Frontline Plus products); and the statements "CAUTION," "Keep out of reach of children," and "See full label for additional directions." Text is in English only.

#1 is the most important feature to differentiate between real and fake Frontline Plus products.
#2-#5 are characteristics of Frontline Plus products packaged for the US market.
Frontline Plus are only manufactured in France, packed according to various countries' rules and regulations and shipped out to their destinations by Merial, France. The packagings may differ, especially in the units of measurements.