Siddha Makardhwaj is a siddha or mineral and herbal formulation contained in a tablet form.

Its usage:
It is used for rejuvenation and anti-aging treatment
It is used in aphrodisiac therapy.
It is also used in convalescent therapy.
Effect on Tridosha – Balances Vata, Pitta and Kapha

Dosage:
125 mg to 250 mg – 1 – 2 tablets once or twice a day with milk before or after food or as directed by Ayurvedic doctor.
Overdosage may cause side effects like tremors, dizziness etc.

Siddha Makardhwaj ingredients:
Parada – Purified and processed Mercury   – 160 grams
Gandhaka – Purified and processed Sulphur – 80 gramsSwarna Bhasma – Gold Bhasma – 40 grams
The above combination of minerals are subjected to a process called as Kupipakva method to obtain Siddha Makaradhwaja.

Reference : Rasa Tarangini.