Nooshin Hussainy
Analyst · BTIG
Thanks, Bill. Today, I would like to share details on our financial results for the fourth quarter and year ended December 31, 2019. I will compare fourth quarter 2019 to third quarter 2019. As I believe sequential growth is what the majority of investors are most interested and given the pivot in our business model in the second quarter of 2019. I will then provide a comparison of full year 2019 versus 2018 financial results. Lastly, I will discuss our recently announced equity line with Lincoln Park Capital.
Fourth quarter revenue was reported at $786,000 compared with $333,000 in the third quarter of 2019. Revenues in the fourth quarter of 2019 included the first full quarter of operations from the retail treatment center model, U.S. physician customer revenues and sales to our international distributors as compared to sales on ETU as physician customers in the third quarter of 2019.
In the fourth quarter, we recognized approximately $140,000 in revenue from the new retail treatment center model, but collected cash of almost $350,000, which is reflected in cash from operations. As a reminder, net revenue from the treatment center model is recognized in line with the delivery of services, while for cash payment, for -- the treatment package is collected upfront, prior to the delivery of services. The majority of net revenue is recognized over the course of balloon placements during the first 3 months of treatment, with the balance expected to be recognized in future quarters. As a result, there's a lag between cash collection and recognized revenue.
U.S. physician revenue was approximately $340,000 and sales to our international distributors contributed $300,000 to fourth quarter revenue, bringing total revenue in Q4 to $786,000. This compared to approximately $330,000 of sales only to U.S. physician customers in third quarter 2019.
Cost of revenue was $626,000 in Q4 as compared to $626,000 in Q3. Gross profit for the fourth quarter of 2019 was $238,000, which was an improvement from a gross deficit of $79,000 in the third quarter of 2019.
Increased volume and absorption of overheads contributed to the sequential improvement in gross profit. Research and development expense for the fourth quarter of 2019 totaled approximately $1,500,000 compared to $1,200,000 in the third quarter of 2019.
Increased enrollment and the post-approval study tied to our original FDA approval through the sequential increase. Furthermore, we continue to make investments to support improvements of our recently approved Obalon Navigation System and Obalon Touch Dispenser as well as continued development of our new product pipeline.
Sales and the general administration expense for the fourth quarter totaled $3,643,000, up from $2,489,000 in the third quarter of 2019.
And increase in D&O liability insurance rates, marketing expenses for the San Diego Obalon Center of Weight Loss, legal and other onetime expenses contributed to the sequential increase.
The operating loss for the quarter was approximately $5 million, which was up to $3,663,000 in the Q3 2019. Net loss for the fourth quarter of 2019 was approximately $4,900,000 or $0.64 per share based on 7,700,000 weighted diluted average common shares outstanding, as compared to a net loss of approximately $3,700,000 or $0.61 per share based on 6,100,000 weighted diluted average common shares outstanding in the third quarter of 2019.
Full year 2019 revenue was reported at approximately $3,300,000 as compared to $9,100,000 for the full year of 2018. U.S. revenue of $2,400,000 decreased from $4,700,000. International revenue of $1 million in 2019 compared to $4,400,000 of international revenue in 2018.
Gross profit for the full year of 2019 was $331,000, resulting in a gross margin of 10% as compared to approximately $3,700,000 for the first quarter of 2018 and a gross margin of 40%. Research and development expense totaled to approximately $6,900,000 for the full year of 2019 as compared to $10,700,000 for the full year of 2018.
Selling, general and administrative expenses decreased to approximately $16,700,000 for the full year of 2019 as compared to $29,900,000 for the full year of 2018. Operating loss for the full year of 2019 was approximately $23,200,000 compared to an operating loss of $37 million for the full year of 2018.
Net loss was reported at $23,700,000 for the full year of 2019 compared to a net loss of $37,400,000 for the full year of 2018. The net loss per share was $5.03 for the full year of 2019 as compared to the net loss per share of $19.64 for the full year of 2018.
Lastly, I would like to touch on our recent financing agreement with Lincoln Park Capital, which could enable us to access up to $15 million over the next 36 months. The intention for this agreement is to help fund expansion of our retail treatment center model. We have filed an S-1 as part of this agreement, and is expected to go effective next month. It is important to note that the equity line with Lincoln Park would provide us the ability to sell shares of our common stock at purchase price that are based on prevailing market rates. It does not include warrants, derivatives, financials or business covenants, and provides us the flexibility to risk capital opportunistically and cost effectively. Most importantly, Obalon is not obligated to sell shares to Lincoln Park, but has the ability to, at our discretion, subject to various conditions.
As a reminder, we ended Q4 2019 with $14,100,000 cash and cash equivalents and short-term investments and no debt. And with that, my comments are complete, and I will turn the call back to Bill.