From What was Prophet Muhammad Created?

He was created from Nutfah (drops of semen - male and female discharges).

Evidence from the Noble Qur'an
{It is He Who created you (Adam) from dust, then from a Nutfah}, {Soorah Ghaafir, verse 67]

Evidence from the authentic Sunnah
((In every one of you, all components are created together in your mother’s womb by 40 days)), [Transmitted by al-Bukhaaree and Muslim]