Exhibit 4.1

THIS SECURITY HAS NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS. THIS SECURITY MAY BE PLEDGED IN CONNECTION WITH A BONA FIDE MARGIN ACCOUNT OR OTHER LOAN SECURED BY SUCH SECURITIES.

Date of this Note: September 25, 2024	Original Principal Amount:	$	1,000,000
Final Maturity Date: September 25, 2025	Interest Rate:		18	%

iSPECIMEN, INC.

SENIOR NOTE

THIS SENIOR NOTE (this “Note”) is a duly authorized and validly issued promissory note of iSpecimen Inc., a Delaware corporation (the “Company”), designated as a senior note.

FOR VALUE RECEIVED, the Company promises to pay to 1396974 BC LTD. or its registered assigns (“Holder”), the Original Principal Amount of this Note as set forth hereinabove (the “Original Principal Amount”) on the Final Maturity Date set forth hereinabove (the “Final Maturity Date”), or such earlier date as this Note is required or permitted to be repaid as provided hereunder (as the case may be, the “Maturity Date”), and to pay interest to the Holder in accordance with the provisions hereof. This Note is subject to the following additional provisions:

Section 1. Definitions. For the purposes hereof, in addition to the terms defined elsewhere in this Note: (a) capitalized terms not otherwise defined herein shall have the meanings set forth in the Purchase Agreement, and (b) the following terms shall have the following meanings:

“Bankruptcy Event” means any of the following events: (a) the Company or any Significant Subsidiary (as such term is defined in Rule 1-02(w) of Regulation S-X) thereof commences a case or other proceeding under any bankruptcy, reorganization, arrangement, adjustment of debt, relief of debtors, dissolution, insolvency or liquidation or similar law of any jurisdiction relating to the Company or any Significant Subsidiary thereof, (b) there is commenced against the Company or any Significant Subsidiary thereof any such case or proceeding that is not dismissed within 60 days after commencement, (c) the Company or any Significant Subsidiary thereof is adjudicated insolvent or bankrupt or any order of relief or other order approving any such case or proceeding is entered, (d) the Company or any Significant Subsidiary thereof suffers any appointment of any custodian or the like for it or any substantial part of its property that is not discharged or stayed within 60 calendar days after such appointment, (e) the Company or any Significant Subsidiary thereof makes a general assignment for the benefit of creditors, (f) the Company or any Significant Subsidiary thereof calls a meeting of its creditors with a view to arranging a composition, adjustment or restructuring of its debts, (g) the Company or any Significant Subsidiary thereof admits in writing that it is generally unable to pay its debts as they become due, (h) the Company or any Significant Subsidiary thereof, by any act or failure to act, expressly indicates its consent to, approval of or acquiescence in any of the foregoing or takes any corporate or other action for the purpose of effecting any of the foregoing.

“Event of Default” shall have the meaning set forth in Section 5(a).

“Fundamental Transaction” shall mean and include any of the following: (i) the merger or consolidation of the Company with or into another Person; (ii) any sale, lease, license, assignment, transfer, conveyance or other disposition of all or substantially all of the Company’s assets in one or a series of related transactions(including any asset or group of assets, regardless whether then so classified by the Company, which would constitute a Significant Subsidiary, as such term is defined in Rule 1-02(w) of Regulation S-X), (iii) any, direct or indirect, purchase offer, tender offer or exchange offer (whether by the Company or another Person) is completed pursuant to which holders of Common Stock are permitted to sell, tender or exchange their shares for other securities, cash or property and has been accepted by the holders of 50% or more of the outstanding Common Stock, (iv) the Company, directly or indirectly, in one or more related transactions effects any reclassification, reorganization or recapitalization of the Common Stock or any compulsory share exchange pursuant to which the Common Stock is effectively converted into or exchanged for other securities, cash or property, or (v) the Company, directly or indirectly, in one or more related transactions consummates a stock or share purchase agreement or other business combination (including, without limitation, a reorganization, recapitalization, spin-off, merger or scheme of arrangement) with another Person or group of Persons whereby such other Person or group acquires more than 50% of the outstanding shares of Common Stock (not including any shares of Common Stock held by the other Person or other Persons making or party to, or associated or affiliated with the other Persons making or party to, such stock or share purchase agreement or other business combination).

“Indebtedness” means any liabilities of the Company for borrowed money or amounts owed and all guaranties made by the Company of borrowed money or amounts owed by others.

“Mandatory Default Amount” means, with respect to this Note at any time: (A) the product of (i) the sum of: (1) the outstanding balance of the Original Principal Amount of this Note at such time, plus (2) all accrued and unpaid interest hereunder at such time and (ii) 120%, plus (B) all liquidated damages and other amounts, costs, expenses and/or liquidated damages due under or in respect of this Note, if any.

“Original Issue Date” means the “Date of this Note” as set forth hereinabove.

“Payment Amount” means, with respect to this Note at any time, the sum of: (1) the outstanding balance of the Original Principal Amount of this Note at such time, plus (2) all accrued and unpaid interest hereunder at such time, plus (3) all liquidated damages and other amounts, costs, expenses and/or liquidated damages due under or in respect of this Note, if any.

“Purchase Agreement” means the Note Purchase Agreement, dated as of September 18, 2024 by and among the Company and the original holder of this Note, as amended, modified, or supplemented from time to time in accordance with its terms.

“Securities Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

Section 2. Interest and Payment.

(a)            The Original Principal Amount of this Note shall bear interest accruing at eighteen percent (18%) per annum, calculated on the basis of a 360-day year, consisting of twelve 30 calendar day periods, and shall accrue daily commencing on the Original Issue Date until payment in full of this Note.

(b)            On the Maturity Date, the entire Payment Amount (or, if an Event of Default shall have previously occurred, the Mandatory Default Amount) shall become due and payable. The Company may prepay this Note in full at any time after the Original Issue Date in an amount equal to the Payment Amount, without premium or penalty; provided, however, that if an Event of Default shall have previously occurred, then the Company shall pay the Mandatory Default Amount.

Section 3. Registration of Transfers and Exchanges.

(a)            Different Denominations. This Note is exchangeable for an equal aggregate Original Principal Amount of this Note of different authorized denominations, as requested by the Holder surrendering the same. No service charge will be payable for such registration of transfer or exchange.

(b)            Investment Representations. This Note has been issued subject to certain investment representations of the original Holder set forth in the Purchase Agreement and may be transferred or exchanged only in compliance with the Purchase Agreement and applicable federal and state securities laws and regulations.

(c)            Reliance on Note Register. Prior to due presentment for transfer to the Company of this Note, the Company and any agent of the Company may treat the Person in whose name this Note is duly registered on its official registry of Notes as the owner hereof for the purpose of receiving payment as herein provided and for all other purposes, whether or not this Note is overdue, and neither the Company nor any such agent shall be affected by notice to the contrary.

Section 4. Negative Covenants. As long as any portion of this Note remains outstanding, unless the holders of a majority in Original Principal Amount of the then outstanding Note shall have otherwise given prior written consent, the Company shall not, and shall not permit any of its Subsidiaries (if any) to, directly or indirectly:

(a)            amend its organization documents, including, without limitation, its certificate of incorporation and bylaws, in any manner that materially and adversely affects any rights of holders of a Note;

(b)            repay, repurchase or offer to repay, repurchase or otherwise acquire more than a de minimis number of shares of its Common Stock or Common Stock Equivalents other than (i) as required under the Transaction Documents, (ii) repurchases of Common Stock or Common Stock Equivalents of departing officers and directors of the Company, provided that such repurchases shall not exceed an aggregate of $25,000 for all officers and directors during the term of this Note, (iii) repurchases of Common Stock or Common Stock Equivalents, pursuant to existing repurchase agreements, provided that such repurchases shall not exceed an aggregate of $25,000 during the term of this Note, or (iv) shares of Common Stock and Common Stock Equivalents which do not vest or are otherwise forfeited, provided (in case of forfeiture) that such Common Stock and Common Stock Equivalents are not acquired for cash;

(c)            repay, repurchase or offer to repay, repurchase or otherwise acquire any Indebtedness, other than the Note, if on a pro-rata basis, and the Credit Line, other than regularly scheduled principal and interest payments as such terms are in effect as of the Original Issue Date; provided that no Event of Default shall then exist or occur or exist by reason thereof; and provided further that is acknowledged and understood by the Holder that nothing contained herein shall prevent the Company from being able to pay all of its accounts payable in the ordinary course of business;

(d)            pay cash dividends or distributions on any equity securities of the Company;

(e)            enter into any material transaction with any Affiliate of the Company, unless such transaction is made on an arm’s-length basis and expressly approved by a majority of the disinterested directors of the Company (even if less than a quorum otherwise required for board approval); or

(f)            enter into any agreement with respect to any of the foregoing.

Section 5. Events of Default.

(a)            “Event of Default” means, wherever used herein, any of the following events (whatever the reason for such event and whether such event shall be voluntary or involuntary or effected by operation of law or pursuant to any judgment, decree or order of any court, or any order, rule or regulation of any administrative or governmental body):

(i)            any default in the payment of the Payment Amount (or, if an Event of Default shall have previously occurred, the Mandatory Default Amount) as and when the same shall become due and payable (whether on the Maturity Date, by mandatory prepayment, acceleration or otherwise) which default is not cured within five (5) Business Days;

(ii)            any of the Investor Board Member Nominees shall have been removed from the Board of Directors (and not promptly replaced on the Board of Directors by a Replacement Nominee) without the prior written consent of the Holder;

(iii)            the Company shall fail to observe or perform any other covenant or agreement contained in the Note, which failure is not cured, if possible to cure, within the earlier to occur of (A) two (2) Business Days after notice of such failure sent by the Holder or by any other Holder to the Company and (B) five (5) Business Days after the Company has become or should have become aware of such failure;

(iv)            a default or event of default (subject to any grace or cure period provided in the applicable agreement, document or instrument) shall occur under (A) any of the Transaction Documents, or (B) any other material agreement, lease, document or instrument to which the Company or any Subsidiary is obligated (and not covered by clause (vii) below);

(v)            any material representation or warranty made in this Note, any other Transaction Documents, any written statement pursuant hereto or thereto or any other report, financial statement or certificate made or delivered to the Holder or any other Holder shall be untrue or incorrect in any material respect as of the date when made;

(vi)            the Company or any Significant Subsidiary (as such term is defined in Rule 1-02(w) of Regulation S-X) shall be subject to a Bankruptcy Event;

(vii)            the Company shall default on any of its obligations under any mortgage, credit agreement or other facility, indenture agreement, capital lease, factoring agreement or other instrument under which there may be issued, or by which there may be secured or evidenced, any Indebtedness for borrowed money or money due under any long term leasing or factoring arrangement that (a) involves an obligation greater than $50,000, whether such Indebtedness now exists or shall hereafter be created, and (b) results in such Indebtedness becoming or being declared due and payable prior to the date on which it would otherwise become due and payable;

(viii)            the Company shall be a party to any change of control transaction or Fundamental Transaction or shall agree to sell or dispose of all or in excess of 33% of its assets in one transaction or a series of related transactions (whether or not such sale would constitute a change of control transaction); or

(ix)            a final non-appealable judgment by any competent court of competent jurisdiction for the payment of money in an amount of at least $50,000 is rendered against the Company, and the same remains undischarged and unpaid for a period of 45 days during which execution of such judgment is not effectively stayed.

(b)            Remedies Upon Event of Default. If any Event of Default occurs, the Mandatory Default Amount of this Note shall become, at the Holder’s election, immediately due and payable in cash. Upon the payment in full of the Payment Amount (or, if an Event of Default shall have previously occurred, the Mandatory Default Amount) in accordance with the terms of this Note, the Holder shall promptly surrender this Note to or as directed by the Company. In connection with such acceleration described herein, the Holder need not provide, and the Company hereby waives, any presentment, demand, protest or other notice of any kind, and the Holder may immediately and without expiration of any grace period enforce any and all of its rights and remedies hereunder and all other remedies available to it under applicable law. Such acceleration may be rescinded and annulled by Holder at any time prior to payment hereunder and the Holder shall have all rights as a holder of the Note until such time, if any, as the Holder receives full payment pursuant to this Section 5(b). No such rescission or annulment shall affect any subsequent Event of Default or impair any right consequent thereon.

Section 6. Miscellaneous.

(a)            Notices. Any and all notices or other communications or deliveries to be provided by the Holder hereunder shall be in writing and delivered personally, by email attachment, or sent by a nationally recognized overnight courier service, addressed to the Company, at the address set forth on in the Purchase Agreement, or such other, email address, or address as the Company may specify for such purposes by notice to the Holder delivered in accordance with this Section 6(a). Any and all notices or other communications or deliveries to be provided by the Company hereunder shall be in writing and delivered personally, by facsimile, by email attachment, or sent by a nationally recognized overnight courier service addressed to each Holder at the facsimile number, email address or address of the Holder appearing on the books of the Company, or if no such facsimile number or email attachment or address appears on the books of the Company, at the principal place of business of such Holder, as set forth in the Purchase Agreement. Any notice or other communication or deliveries hereunder shall be deemed given and effective on the earliest of: (i) the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number or email attachment to the email address set forth on the signature pages attached hereto prior to 5:30 p.m. (Eastern time) on any date, (ii) the next Business Day after the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number or email attachment to the email address set forth on the signature pages attached hereto on a day that is not a Business Day or later than 5:30 p.m. (Eastern time) on any Business Day, (iii) the second Business Day following the date of mailing, if sent by U.S. nationally recognized overnight courier service, or (iv) upon actual receipt by the party to whom such notice is required to be given.

(b)            Absolute Obligation; Ranking. Except as expressly provided herein, no provision of this Note shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the principal of, liquidated damages and accrued interest, as applicable, on this Note at the time, place, and rate, and in the coin or currency, herein prescribed. This Note is a direct debt obligation of the Company. This Note is a senior direct debt obligation of the Company that ranks (x) pari passu with all other Notes (if any) now or hereafter issued under the terms of the Purchase Agreement, and (y) senior or pari passu with all other Indebtedness of the Company.

(c)            Lost or Mutilated Note. If this Note shall be mutilated, lost, stolen or destroyed, the Company shall execute and deliver, in exchange and substitution for and upon cancellation of a mutilated Note, or in lieu of or in substitution for a lost, stolen or destroyed Note, a new Note for the Original Principal Amount of this Note so mutilated, lost, stolen or destroyed, but only upon receipt of evidence of such loss, theft or destruction of such Note, and of the ownership hereof, reasonably satisfactory to the Company.

(d)            Governing Law. Section 5.07 of the Purchase Agreement shall apply with respect to any matters relating to this Note.

(e)            Waiver. Any waiver by the Company or the Holder of a breach of any provision of this Note shall not operate as or be construed to be a waiver of any other breach of such provision or of any breach of any other provision of this Note. The failure of the Company or the Holder to insist upon strict adherence to any term of this Note on one or more occasions shall not be considered a waiver or deprive that party of the right thereafter to insist upon strict adherence to that term or any other term of this Note on any other occasion. Any waiver by the Company or the Holder must be in writing.

(f)            Severability. If any provision of this Note is invalid, illegal or unenforceable, the balance of this Note shall remain in effect, and if any provision is inapplicable to any Person or circumstance, it shall nevertheless remain applicable to all other Persons and circumstances. If it shall be found that any interest or other amount deemed interest due hereunder violates the applicable law governing usury, the applicable rate of interest due hereunder shall automatically be lowered to equal the maximum rate of interest permitted under applicable law. The Company covenants (to the extent that it may lawfully do so) that it shall not at any time insist upon, plead, or in any manner whatsoever claim or take the benefit or advantage of, any stay, extension or usury law or other law which would prohibit or forgive the Company from paying all or any portion of the principal of or interest on this Note as contemplated herein, wherever enacted, now or at any time hereafter in force, or which may affect the covenants or the performance of this Note, and the Company (to the extent it may lawfully do so) hereby expressly waives all benefits or advantage of any such law, and covenants that it will not, by resort to any such law, hinder, delay or impede the execution of any power herein granted to the Holder, but will suffer and permit the execution of every such as though no such law has been enacted.

(g)            Remedies, Characterizations, Other Obligations, Breaches and Injunctive Relief. The remedies provided in this Note shall be cumulative and in addition to all other remedies available under this Note and any of the other Transaction Documents at law or in equity (including a decree of specific performance and/or other injunctive relief), and nothing herein shall limit the Holder’s right to pursue actual and consequential damages for any failure by the Company to comply with the terms of this Note. The Company covenants to the Holder that there shall be no characterization concerning this instrument other than as expressly provided herein. Amounts set forth or provided for herein with respect to payments and the like (and the computation thereof) shall be the amounts to be received by the Holder and shall not, except as expressly provided herein, be subject to any other obligation of the Company (or the performance thereof). The Company acknowledges that a breach by it of its obligations hereunder will cause irreparable harm to the Holder and that the remedy at law for any such breach may be inadequate. The Company therefore agrees that, in the event of any such breach or threatened breach, the Holder shall be entitled, in addition to all other available remedies, to an injunction restraining any such breach or any such threatened breach, without the necessity of showing economic loss and without any bond or other security being required. The Company shall provide all information and documentation to the Holder that is reasonably requested by the Holder to enable the Holder to confirm the Company’s compliance with the terms and conditions of this Note.

(h)            Next Business Day. Whenever any payment or other obligation hereunder shall be due on a day other than a Business Day, such payment shall be made on the next succeeding Business Day.

(i)            Headings. The headings contained herein are for convenience only, do not constitute a part of this Note and shall not be deemed to limit or affect any of the provisions hereof.

Section 7. Amendments; Waivers. Any modifications, amendments or waivers of the provisions hereof shall be subject to Section 5.04 of the Purchase Agreement.

Section 8. Usury. To the extent it may lawfully do so, the Company hereby agrees not to insist upon or plead or in any manner whatsoever claim and will resist any and all efforts to be compelled to take the benefit or advantage of, usury laws wherever enacted, now or at any time hereafter in force, in connection with any action or proceeding that may be brought by any Holder in order to enforce any right or remedy under any Transaction Document. Notwithstanding any provision to the contrary contained in any Transaction Document, it is expressly agreed and provided that the total liability of the Company under the Transaction Documents for payments in the nature of interest shall not exceed the maximum lawful rate authorized under applicable law (the “Maximum Rate”), and, without limiting the foregoing, in no event shall any rate of interest or default interest, or both of them, when aggregated with any other sums in the nature of interest that the Company may be obligated to pay under the Transaction Documents exceed such Maximum Rate. It is agreed that if the maximum contract rate of interest allowed by law and applicable to the Transaction Documents is increased or decreased by statute or any official governmental action subsequent to the date hereof, the new maximum contract rate of interest allowed by law will be the Maximum Rate applicable to the Transaction Documents from the effective date thereof forward, unless such application is precluded by applicable law. If under any circumstances whatsoever, interest in excess of the Maximum Rate is paid by the Company to any Holder with respect to indebtedness evidenced by the Transaction Documents, such excess shall be applied by such Holder to the unpaid principal amount of any such indebtedness or be refunded to the Company, the manner of handling such excess to be at such Holder’s election.

IN WITNESS WHEREOF, the Company has caused this Note to be duly executed by a duly authorized officer as of the date first above indicated.

iSPECIMEN, INC.
By:	/s/ Tracy Curley
Name: Tracy Curley
Title: Chief Executive Officer