For the three months ended September 30, 2024 and 2023, selling, general and administrative expenses were $2,735,419 and $4,612,824, respectively, representing a decrease of $1,877,405 or 41%. The decrease is primarily due to a reduction in stock-based compensation due to clawing back amortization for unvested, cancelled restricted stock awards of $638,592, a decrease in advertising expense of $571,238 due to a sponsorship agreement terminating in 4Q23, and a decrease of $481,661 in depreciation expense primarily due to leasehold improvements for the San Diego facility being fully depreciated in 2Q24.
For the nine months ended September 30, 2024 and 2023, selling, general and administrative expenses were $11,542,820 and $14,578,145, respectively, representing a decrease of $3,035,325 or 21%. The decrease is primarily due to a planned decrease in advertising and marketing services of $1,345,581, a decrease in stock-based compensation of of $687,004 primarily due to clawing back amortization for unvested, cancelled restricted stock units, a planned decrease in outsourced professional services of $602,438, and a decrease in labor costs of $182,533 due to the workforce reduction in December of 2023.
Other (Expense) Income
For the three months ended September 30, 2024 and 2023, other expense, net, was a net expense of $293,464 and $465,246, respectively, representing a decrease of $171,782, or 37%. The change is primarily attributable to a decrease in interest expense of $158,686 due to the full repayment of the prepaid advance liability during 1Q24, a decrease of $56,210 due to the change in fair value of of accrued issuable equity, partially offset by an increase of $43,114 for amortization of debt discount in connection with merchant cash advances.
For the nine months ended September 30, 2024 and 2023, other expense, net, was a net expense of $1,209,073 and $1,062,401, respectively, representing an increase of $146,672, or 14%. The change is primarily attributable to an increase of $284,516 for amortization of debt discount in connection with merchant cash advances, an increase of $180,289 for the change in fair value of accrued issuable equity and $31,358 related to a 2024 loss on the extinguishment of debt related to the Prepaid Advance Liability, partially offset by a decrease of $349,491 in interest due to the full repayment of the prepaid advance liability during 1Q24.
Liquidity and Capital Resources
As of September 30, 2024 and December 2023, we had cash balances of $912,417 and $1,194,764, respectively, and a working capital deficit of $1,157,755 and $2,994,753, respectively.
For the nine months ended September 30, 2024 and 2023, net cash used in operating activities was $12,498,818 and $10,893,050, respectively. Our net cash used in operating activities for the nine months ended September 30, 2024, was primarily attributable to our net loss of $12,903,168, adjusted for non-cash expenses in the aggregate amount of $4,721,844, plus $4,317,494 of net cash used to fund changes in the levels of operating assets and liabilities. Our net cash used in operating activities for the nine months ended September 30, 2023, was primarily attributable to our net loss of $18,500,127, adjusted for non-cash expenses in the aggregate amount of $4,968,456, as well as $2,638,621 of net cash provided by changes in the levels of operating assets and liabilities.
For the nine months ended September 30, 2024 and 2023, net cash used in investing activities was $211,005 and $993,699, respectively. Net cash used in investing activities during the nine months ended September 30, 2024, was related to purchases of property and equipment of $188,267 and deposits paid for purchases of property and equipment of $22,738. Net cash used in investing activities during the nine months ended September 30, 2023, was related to deposits paid for purchases of property and equipment of $621,107, purchases of property and equipment of $237,592, and an acquisition of intangible assets of $135,000.
For the nine months ended September 30, 2024 and 2023, net cash provided by financing activities was $12,427,476 and $2,720,501, respectively. Net cash provided by financing activities during the nine months ended September 30, 2024, was primarily due to proceeds from SEPA Advance Notices totaling $9,104,950, net proceeds from ATM equity financing totaling $3,327,372, and net proceeds from notes payable totaling $2,563,900, partially offset by notes payable repayments of $2,439,855, and payments for deferred financing costs of $128,041. Net cash provided by financing activities during the nine months ended September 30, 2023 was due to the net proceeds from a public offering of $2,554,750 and net proceeds from prepaid advances of $1,970,000, partially offset by repayments of the Prepaid Advance of $1,575,000, and repurchases of common stock of $229,249.
Future cash requirements for our current liabilities as of September 30, 2024, include $4,375,171 for accounts payable and accrued expenses, $1,245,529 for secured notes payable and $507,959 for payments under operating and finance leases.
Future cash requirements for long-term liabilities as of September 30, 2024, include $930,361 for operating and finance leases, and $266,604 for notes payable.