Where Ovidrel is much more superior to Pregnyl, is that the alpha unit stimulates the FSH, LH and TSH production simultaneously - so, it repairs your testosterone function, sperm production and thyroid function in one go, whereas Pregnyl does only the testosterone function.
Another reason for Ovidrel's use above that of Pregnyl, is that the whole month's worth is cheaper, it can be mixed and kept at room temperature and the same vial can be used for more than 30 days after being mixed. Smaller dosages can be used at more regular intervals. Pregnyl, on the otherhand, comes only in 1500 or 5000IU(too much) ampules, is very unstable after being mixed, must be kept at 2-8 degrees and all be used within 48h of mixing.
