"more frequent doses" is correct and usable in written English.
You can use it to describe something that is given or taken in a greater frequency than usual, for example: "He began to take more frequent doses of his medication to get better control of his symptoms."
In some clinics, women with advanced breast or ovarian cancer are being given smaller, more frequent doses of chemotherapy to reduce side effects.
But giving Venofer, the iron drug, in smaller and more frequent doses would increase needle use, violating that policy.
After regular use, their effect tends to lessen, so larger and more frequent doses are necessary until finally they cease to be effective.
If the plasma half-life (t1/2)—the time it takes for the plasma concentration to fall to 50percentt of its starting value is long, doses can be given at relatively long intervals (e.g., once per day), but if the t1/2 is short (less than about 24 hours), more frequent doses will be necessary.
RESULTS: Eighty-nine of 115 students (69%) used their ADHD medications as prescribed, whereas 36 (31%) had misused during college by taking larger or more frequent doses than prescribed or by using someone else's medication.
They soon realized Adam needed stronger, more frequent doses, but they weren't sure his body could handle it.
More frequent dosing does not increase activity.
Patients without heart risks may be safe even with more frequent dosing, these data suggest.
Reduced doses and more frequent dosing could dilute out the adverse effects and still produce some beneficial effects.
They could sleep through the night — a crucial improvement over conventional painkillers, such as morphine, which require more frequent dosing.
The impact of missed doses is decreased by more frequent dosing despite the fact that compliance decreases with increased dosing frequency.
