diff --git a/packages/better-auth/src/cookies/cookie-utils.ts b/packages/better-auth/src/cookies/cookie-utils.ts
index e0feba6e93..96ada13fda 100644
--- a/packages/better-auth/src/cookies/cookie-utils.ts
+++ b/packages/better-auth/src/cookies/cookie-utils.ts
@@ -26,11 +26,55 @@ export function stripSecureCookiePrefix(cookieName: string): string {
 	return cookieName;
 }
 
+/**
+ * Split `Set-Cookie` header, handling commas in `Expires` dates.
+ */
+export function splitSetCookieHeader(setCookie: string): string[] {
+	if (!setCookie) return [];
+
+	const result: string[] = [];
+	let current = "";
+	let i = 0;
+
+	while (i < setCookie.length) {
+		const c = setCookie[i];
+
+		if (c === ",") {
+			const lower = current.toLowerCase();
+			if (lower.includes("expires=") && !lower.includes("gmt")) {
+				current += c;
+				i++;
+			} else {
+				const trimmed = current.trim();
+				if (trimmed) {
+					result.push(trimmed);
+				}
+				current = "";
+				i++;
+				if (i < setCookie.length && setCookie[i] === " ") {
+					i++;
+				}
+			}
+			continue;
+		}
+
+		current += c;
+		i++;
+	}
+
+	const trimmed = current.trim();
+	if (trimmed) {
+		result.push(trimmed);
+	}
+
+	return result;
+}
+
 export function parseSetCookieHeader(
 	setCookie: string,
 ): Map<string, CookieAttributes> {
 	const cookies = new Map<string, CookieAttributes>();
-	const cookieArray = setCookie.split(", ");
+	const cookieArray = splitSetCookieHeader(setCookie);
 
 	cookieArray.forEach((cookieString) => {
 		const parts = cookieString.split(";").map((part) => part.trim());
@@ -107,12 +151,9 @@ export function setCookieToHeader(headers: Headers) {
 			}
 		});
 
-		const setCookieHeaders = setCookieHeader.split(",");
-		setCookieHeaders.forEach((header) => {
-			const cookies = parseSetCookieHeader(header);
-			cookies.forEach((value, name) => {
-				cookieMap.set(name, value.value);
-			});
+		const cookies = parseSetCookieHeader(setCookieHeader);
+		cookies.forEach((value, name) => {
+			cookieMap.set(name, value.value);
 		});
 
 		const updatedCookies = Array.from(cookieMap.entries())
diff --git a/packages/better-auth/src/cookies/cookies.test.ts b/packages/better-auth/src/cookies/cookies.test.ts
index 66ddfc7600..8e16c78e79 100644
--- a/packages/better-auth/src/cookies/cookies.test.ts
+++ b/packages/better-auth/src/cookies/cookies.test.ts
@@ -219,6 +219,24 @@ describe("cookie-utils parseSetCookieHeader", () => {
 		const map = parseSetCookieHeader(header);
 		expect(map.get("a")?.value).toBe("1");
 		expect(map.get("b")?.value).toBe("2");
+		expect(map.get("a")?.expires).toEqual(
+			new Date("Wed, 21 Oct 2015 07:28:00 GMT"),
+		);
+		expect(map.get("b")?.expires).toEqual(
+			new Date("Thu, 22 Oct 2015 07:28:00 GMT"),
+		);
+	});
+
+	it("handles cookie with Expires followed by cookie without Expires", () => {
+		const map = parseSetCookieHeader(
+			"session=xyz; Expires=Mon, 01 Jan 2026 00:00:00 GMT, token=abc",
+		);
+		expect(map.get("session")?.value).toBe("xyz");
+		expect(map.get("session")?.expires).toEqual(
+			new Date("Mon, 01 Jan 2026 00:00:00 GMT"),
+		);
+		expect(map.get("token")?.value).toBe("abc");
+		expect(map.get("token")?.expires).toBeUndefined();
 	});
 });
 
diff --git a/packages/expo/src/client.ts b/packages/expo/src/client.ts
index 860f56a3ac..9c7cd4d0fd 100644
--- a/packages/expo/src/client.ts
+++ b/packages/expo/src/client.ts
@@ -5,6 +5,7 @@ import type {
 } from "@better-auth/core";
 import { safeJSONParse } from "@better-auth/core/utils";
 import {
+	parseSetCookieHeader,
 	SECURE_COOKIE_PREFIX,
 	stripSecureCookiePrefix,
 } from "better-auth/cookies";
@@ -19,79 +20,6 @@ if (Platform.OS !== "web") {
 	setupExpoOnlineManager();
 }
 
-interface CookieAttributes {
-	value: string;
-	expires?: Date | undefined;
-	"max-age"?: number | undefined;
-	domain?: string | undefined;
-	path?: string | undefined;
-	secure?: boolean | undefined;
-	httpOnly?: boolean | undefined;
-	sameSite?: ("Strict" | "Lax" | "None") | undefined;
-}
-
-export function parseSetCookieHeader(
-	header: string,
-): Map<string, CookieAttributes> {
-	const cookieMap = new Map<string, CookieAttributes>();
-	const cookies = splitSetCookieHeader(header);
-	cookies.forEach((cookie) => {
-		const parts = cookie.split(";").map((p) => p.trim());
-		const [nameValue, ...attributes] = parts;
-		const [name, ...valueParts] = (nameValue || "").split("=");
-		const value = valueParts.join("=");
-
-		if (!name || value === undefined) {
-			return;
-		}
-
-		const attrObj: CookieAttributes = { value };
-		attributes.forEach((attr) => {
-			const [attrName, ...attrValueParts] = attr.split("=");
-			if (!attrName?.trim()) {
-				return;
-			}
-			const attrValue = attrValueParts.join("=");
-			const normalizedAttrName = attrName.trim().toLowerCase();
-			attrObj[normalizedAttrName as "value"] = attrValue;
-		});
-		cookieMap.set(name, attrObj);
-	});
-	return cookieMap;
-}
-
-function splitSetCookieHeader(setCookie: string): string[] {
-	const parts: string[] = [];
-	let buffer = "";
-	let i = 0;
-	while (i < setCookie.length) {
-		const char = setCookie[i];
-		if (char === ",") {
-			const recent = buffer.toLowerCase();
-			const hasExpires = recent.includes("expires=");
-			const hasGmt = /gmt/i.test(recent);
-			if (hasExpires && !hasGmt) {
-				buffer += char;
-				i += 1;
-				continue;
-			}
-			if (buffer.trim().length > 0) {
-				parts.push(buffer.trim());
-				buffer = "";
-			}
-			i += 1;
-			if (setCookie[i] === " ") i += 1;
-			continue;
-		}
-		buffer += char;
-		i += 1;
-	}
-	if (buffer.trim().length > 0) {
-		parts.push(buffer.trim());
-	}
-	return parts;
-}
-
 interface ExpoClientOptions {
 	scheme?: string | undefined;
 	storage: {
@@ -538,5 +466,6 @@ export const expoClient = (opts: ExpoClientOptions) => {
 	} satisfies BetterAuthClientPlugin;
 };
 
+export { parseSetCookieHeader } from "better-auth/cookies";
 export * from "./focus-manager";
 export * from "./online-manager";