diff --git a/__tests__/synonyms.server.ts b/__tests__/synonyms.server.ts
index 84f020558..48f553508 100644
--- a/__tests__/synonyms.server.ts
+++ b/__tests__/synonyms.server.ts
@@ -4,7 +4,10 @@ import * as awsSDKMock from 'aws-sdk-mock'
 import crypto from 'crypto'
 
 import type { Circular } from '~/routes/circulars/circulars.lib'
-import { createSynonyms, putSynonyms } from '~/routes/synonyms/synonyms.server'
+import {
+  moderatorCreateSynonyms,
+  putSynonyms,
+} from '~/routes/synonyms/synonyms.server'
 
 jest.mock('@architect/functions')
 const synonymId = 'abcde-abcde-abcde-abcde-abcde'
@@ -36,7 +39,7 @@ const exampleCirculars = [
   { Items: [] },
 ]
 
-describe('createSynonyms', () => {
+describe('moderatorCreateSynonyms', () => {
   beforeEach(() => {
     const mockBatchWrite = jest.fn()
     const mockQuery = jest.fn()
@@ -65,7 +68,7 @@ describe('createSynonyms', () => {
     jest.restoreAllMocks()
   })
 
-  test('createSynonyms should write to DynamoDB', async () => {
+  test('moderatorCreateSynonyms should write to DynamoDB', async () => {
     const mockBatchWriteItem = jest.fn(
       (
         params: DynamoDB.DocumentClient.BatchWriteItemInput,
@@ -81,12 +84,12 @@ describe('createSynonyms', () => {
     awsSDKMock.mock('DynamoDB', 'batchWriteItem', mockBatchWriteItem)
 
     const synonymousEventIds = ['eventId1', 'eventId2']
-    const result = await createSynonyms(synonymousEventIds)
+    const result = await moderatorCreateSynonyms(synonymousEventIds)
 
     expect(result).toBe(synonymId)
   })
 
-  test('createSynonyms with nonexistent eventId throws Response 400', async () => {
+  test('moderatorCreateSynonyms with nonexistent eventId throws Response 400', async () => {
     const mockBatchWriteItem = jest.fn(
       (
         params: DynamoDB.DocumentClient.BatchWriteItemInput,
@@ -103,7 +106,7 @@ describe('createSynonyms', () => {
 
     const synonymousEventIds = ['eventId1', 'nope']
     try {
-      await createSynonyms(synonymousEventIds)
+      await moderatorCreateSynonyms(synonymousEventIds)
     } catch (error) {
       // eslint-disable-next-line jest/no-conditional-expect
       expect(error).toBeInstanceOf(Response)
diff --git a/app/email-incoming/circulars/index.ts b/app/email-incoming/circulars/index.ts
index 0a53a4a18..a1dcc3780 100644
--- a/app/email-incoming/circulars/index.ts
+++ b/app/email-incoming/circulars/index.ts
@@ -27,10 +27,7 @@ import {
 import { sendEmail } from '~/lib/email.server'
 import { hostname, origin } from '~/lib/env.server'
 import { putRaw, submitterGroup } from '~/routes/circulars/circulars.server'
-import {
-  createSynonyms,
-  synonymExists,
-} from '~/routes/synonyms/synonyms.server'
+import { tryInitSynonym } from '~/routes/synonyms/synonyms.server'
 
 interface UserData {
   email: string
@@ -103,8 +100,7 @@ export const handler = createEmailIncomingMessageHandler(
     // Removes sub as a property if it is undefined from the legacy users
     if (!circular.sub) delete circular.sub
     const { circularId } = await putRaw(circular)
-    if (eventId && !(await synonymExists({ eventId })))
-      await createSynonyms([eventId])
+    if (eventId) await tryInitSynonym(eventId)
 
     // Send a success email
     await sendSuccessEmail({
diff --git a/app/routes/circulars/circulars.server.ts b/app/routes/circulars/circulars.server.ts
index 2e4dc76e9..36173fc73 100644
--- a/app/routes/circulars/circulars.server.ts
+++ b/app/routes/circulars/circulars.server.ts
@@ -22,7 +22,7 @@ import memoizee from 'memoizee'
 import { dedent } from 'ts-dedent'
 
 import { type User, getUser } from '../_auth/user.server'
-import { createSynonyms, synonymExists } from '../synonyms/synonyms.server'
+import { tryInitSynonym } from '../synonyms/synonyms.server'
 import {
   bodyIsValid,
   formatAuthor,
@@ -313,8 +313,7 @@ export async function put(
   const eventId = parseEventFromSubject(item.subject)
   if (eventId) circular.eventId = eventId
   const result = await putRaw(circular)
-  if (eventId && !(await synonymExists({ eventId })))
-    await createSynonyms([eventId])
+  if (eventId) await tryInitSynonym(eventId)
   return result
 }
 
diff --git a/app/routes/synonyms.new.tsx b/app/routes/synonyms.new.tsx
index 665ce4770..3c0c064fa 100644
--- a/app/routes/synonyms.new.tsx
+++ b/app/routes/synonyms.new.tsx
@@ -28,7 +28,7 @@ import { getUser } from './_auth/user.server'
 import { moderatorGroup } from './circulars/circulars.server'
 import {
   autoCompleteEventIds,
-  createSynonyms,
+  moderatorCreateSynonyms,
 } from './synonyms/synonyms.server'
 import DetailsDropdownContent from '~/components/DetailsDropdownContent'
 import { getFormDataString } from '~/lib/utils'
@@ -40,7 +40,7 @@ export async function action({ request }: ActionFunctionArgs) {
   const data = await request.formData()
   const eventIds = getFormDataString(data, 'synonyms')?.split(',')
   if (!eventIds) throw new Response(null, { status: 400 })
-  const synonymId = await createSynonyms(eventIds)
+  const synonymId = await moderatorCreateSynonyms(eventIds)
   return redirect(`/synonyms/${synonymId}`)
 }
 
diff --git a/app/routes/synonyms/synonyms.server.ts b/app/routes/synonyms/synonyms.server.ts
index 0d6c1f202..d364deeaa 100644
--- a/app/routes/synonyms/synonyms.server.ts
+++ b/app/routes/synonyms/synonyms.server.ts
@@ -6,7 +6,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 import { tables } from '@architect/functions'
-import type { DynamoDBDocument } from '@aws-sdk/lib-dynamodb'
+import { PutItemCommand } from '@aws-sdk/client-dynamodb'
+import { type DynamoDBDocument } from '@aws-sdk/lib-dynamodb'
 import { search as getSearchClient } from '@nasa-gcn/architect-functions-search'
 import crypto from 'crypto'
 
@@ -122,20 +123,6 @@ async function getSynonymMembers(eventId: string) {
   return Items as Circular[]
 }
 
-export async function synonymExists({ eventId }: { eventId: string }) {
-  const db = await tables()
-  const { Items } = await db.synonyms.query({
-    KeyConditionExpression: '#eventId = :eventId',
-    ExpressionAttributeNames: {
-      '#eventId': 'eventId',
-    },
-    ExpressionAttributeValues: {
-      ':eventId': eventId,
-    },
-  })
-  return Items.length >= 1
-}
-
 /*
  * If an eventId already has a synonym and is passed in, it will unlink the
  * eventId from the old synonym and the only remaining link will be to the
@@ -144,17 +131,17 @@ export async function synonymExists({ eventId }: { eventId: string }) {
  * BatchWriteItem has a limit of 25 items, so the user may not add more than
  * 25 synonyms at a time.
  */
-export async function createSynonyms(synonymousEventIds: string[]) {
-  const uuid = crypto.randomUUID()
+export async function moderatorCreateSynonyms(synonymousEventIds: string[]) {
   if (!synonymousEventIds.length) {
     throw new Response('EventIds are required.', { status: 400 })
   }
+  const uuid = crypto.randomUUID()
   const db = await tables()
   const client = db._doc as unknown as DynamoDBDocument
   const TableName = db.name('synonyms')
-
   const isValid = await validateEventIds({ eventIds: synonymousEventIds })
   if (!isValid) throw new Response('eventId does not exist', { status: 400 })
+
   await client.batchWrite({
     RequestItems: {
       [TableName]: synonymousEventIds.map((eventId) => ({
@@ -167,6 +154,25 @@ export async function createSynonyms(synonymousEventIds: string[]) {
   return uuid
 }
 
+export async function tryInitSynonym(eventId: string) {
+  const db = await tables()
+  const client = db._doc as unknown as DynamoDBDocument
+  const TableName = db.name('synonyms')
+  try {
+    const params = {
+      TableName,
+      Item: {
+        synonymId: { S: crypto.randomUUID() },
+        eventId: { S: eventId },
+      },
+      ConditionExpression: 'attribute_not_exists(eventId)',
+    }
+    await client.send(new PutItemCommand(params))
+  } catch (error) {
+    if ((error as Error).name !== 'ConditionalCheckFailedException') throw error
+  }
+}
+
 /*
  * If an eventId already has a synonym and is passed in, it will unlink the
  * eventId from the old synonym and the only remaining link will be to the
@@ -195,10 +201,11 @@ export async function putSynonyms({
   const writes = []
   if (subtractions?.length) {
     const subtraction_writes = subtractions.map((eventId) => ({
-      DeleteRequest: {
-        Key: { eventId },
+      PutRequest: {
+        Item: { synonymId: crypto.randomUUID(), eventId },
       },
     }))
+
     writes.push(...subtraction_writes)
   }
   if (additions?.length) {
@@ -233,9 +240,10 @@ export async function deleteSynonyms(synonymId: string) {
       ':synonymId': synonymId,
     },
   })
+
   const writes = results.Items.map(({ eventId }) => ({
-    DeleteRequest: {
-      Key: { eventId },
+    PutRequest: {
+      Item: { synonymId: crypto.randomUUID(), eventId },
     },
   }))
   const params = {