RAVICTI net sales were $0.8 million for the first quarter of 2013, representing orders received by patients post-approval. The FDA granted approval of RAVICTI on February 1, 2013.
Cost of goods sold was $68,000 for the first quarter of 2013. Cost of goods sold related to the sales of RAVICTI is not representative of Hyperion's future expectations of this expense as manufacturing related expenses associated with RAVICTI sales during the first quarter of 2013 were recorded to research and development expenses in periods prior to approval.
Research and development expenses for the first quarter of 2013 were $1.8 million compared with $8.9 million for the same period in 2012. The decrease was primarily due to $5.7 million in expenses incurred in connection with the purchase of RAVICTI in 2012 as well as a decrease in clinical development costs primarily due to the completion of our HE Phase II trial in 2012. Total research and development stock-based compensation expense for the first quarter of 2013 was $0.1 million compared with $37,000 for the same period in 2012.
Selling, general and administrative expenses for the first quarter 2013 were $7.9 million compared to $2.3 million for the same period of 2012. The increase in the first quarter compared to the same period last year was primarily due to an increase in employee-related costs as a result of new hires in the commercial organization, increases in consulting expenses and other commercial and administrative related infrastructure expenses pertaining to the commercialization of RAVICTI. Total selling, general and administrative stock-based compensation expense for the first quarter of 2013 was $0.4 million compared with $41,000 for the same period in 2012.
As of March 31, 2013, Hyperion had cash and cash equivalents of $102.7 million, an increase of $52.8 million from December 31, 2012. The increase is primarily due to net proceeds of $63.7 million received from the Company's follow-on public offering, partially offset by cash used in operations of $10.8 million.