[1][2][3] It has been formulated both as short-acting oil solutions and long-acting microcrystalline aqueous suspensions and is given by injection into muscle either once or continuously at regular intervals.

[11][12][13] EB/P4 is or has been available for use by intramuscular injection both in the form of short-acting oil solutions (e.g., Duogynon, Lutrogen) and long-acting microcrystalline aqueous suspensions (e.g., Clinomin Forte, Sistocyclin).

[6] For comparison, the decidua induction dosage of estradiol valerate and hydroxyprogesterone caproate in oil solution is about the same as that of microcrystalline EB/P4 in aqueous suspension.

[22][5] A study found that a single intramuscular injection of 10 mg microcrystalline EB in aqueous suspension with a 0.05 mm crystal size (similar to that in Sistocyclin) resulted in a maximal 7-fold increase in estradiol excretion on the 2nd day after injection and maintained elevated estradiol excretion for 17 days.

[6] To achieve a longer duration of action, microcrystalline EB/P4 with defined crystal sizes in aqueous suspension was developed, studied in 1954,[42] and marketed under the brand name Sistocyclin shortly thereafter in the 1950s.

[4][5] Today, it is available in a number of places in the world including various Latin American countries, Egypt, Italy, Lebanon, Taiwan, Thailand, Turkey, Malaysia, and Ethiopia.

[1][2][44][45] However, individual formulations of microcrystalline EB in aqueous suspension (brand name Agofollin Depot)[46] and microcrystalline P4 in aqueous suspension (brand name Agolutin Depot)[47] remain available in some countries, including the Czech Republic and Slovakia.