Yes, you need to use both products because Program Plus prevents fleas and Capstar kills fleas.
If you use only Program Plus you don’t have protection for adult fleas and this is the reason you need to use Capstar I will give same information about these products:
PROGRAM PLUS tablets are indicated for the prevention of fleas (Ct. felis, Ct. canis, preadult stages), and for the concurrent prevention of heartworm disease (elimination of 3rd and 4th larval stages of Dirofilaria immitis) and/or treatment of adult stages of gastrointestinal nematodes such as hookworms (Ancylostoma caninum), roundworms (Toxocara canis) and whipworms (Trichuris vulpis) in dogs
Milbemycin oxime, which belongs to the group of macrocyclic lactones, is active against mites, against larval and adult stages of nematodes as well as against larvae of Dirofilaria immitis.
No alteration of reproductive function, neither foetal nor neonatal toxicity has been reported for lufenuron and milbemycin oxime used as a monotherapy in dogs
Capstar is indicated for the treatment of fleas on dogs and cats.
Dosage and administration
Capstar tablets are administered orally at a minimum recommended dose of 1mg/kg, with the following recommendations:
Capstar tablets should be given orally, either directly into the mouth or mixed into a small portion of food and given immediately. Administer on any day when fleas are seen on the animal. No more than one treatment should be given per day.
Effects on fleas may be seen as soon as 15 minutes after administration. Between 95% and 100% efficacy is observed within the first 6 hours and 100% efficacy is reached within 24 hours