Get Blood Glucose by Interval

Retrieves the user's daily, min, max, sum and average values of blood glucose levels within an interval.

Scope: blood_glucose

Request

GET	/1/user/-/health/metrics/glucose/values/[startDate]/[endDate].json

URI Arguments

startDate	required	Start date (inclusive) of the interval to query in format YYYY-MM-DD
endDate	required	End date (inclusive) of the interval to query in format YYYY-MM-DD

Request Headers

authorization	required	Specify the token type and Fitbit user’s access token. Token type: `Bearer`
accept	optional	The media type of the response content the client is expecting. Supported: `application/json`
accept-language	recommended	The measurement unit system to use for response values. See Localization.
accept-locale	optional	The locale to use for response values. See Localization.

Examples

URL
CURL

GET https://api.fitbit.com/1/user/-/health/metrics/glucose/values/2025-12-04/2025-12-05.json

curl -X GET "https://api.fitbit.com/1/user/-/health/metrics/glucose/values/2025-12-04/2025-12-05.json" \
-H "accept: application/json" \
-H "authorization: Bearer <access_token>"

Element Name	Description
[ ]	Array of date entries
date	Date of the entries
minValue	Minimum value for the day
maxValue	Maximum value for the day
numberOfValues	Number of blood glucose values for the day
sumOfValues	Sum of blood glucose values for the day
average	Average blood glucose value for the day
values[]	Array of entries for the day
values : dateTime	Timestamp of the entry
values : value	Blood glucose value
measurementType	Blood glucose measurement source. Supported: `SMBG` - Self-monitored / Glucose meter `CGM` - Continuous glucose monitoring device `LAB_TEST` - Laboratory test `UNSPECIFIED` - Unspecified or manually entered

[
  {
    "date": "2025-12-01",
    "minValue": 120.0,
    "maxValue": 140.0,
    "numberOfValues": 2,
    "sumOfValues": 260.0,
    "average": 130.0,
    "values": [
      {
        "dateTime": "2025-12-01T13:21:00",
        "value": 140.0,
        "measurementType": "UNSPECIFIED"
      },
      {
        "dateTime": "2025-12-01T08:00:00",
        "value": 120.0,
        "measurementType": "UNSPECIFIED"
      }
    ]
  },
  {
    "date": "2025-12-02",
    "minValue": 120.0,
    "maxValue": 120.0,
    "numberOfValues": 1,
    "sumOfValues": 120.0,
    "average": 120.0,
    "values": [
      {
        "dateTime": "2025-12-02T08:00:00",
        "value": 120.0,
        "measurementType": "SMBG"
      }
    ]
  }
]

Response Headers

content-type	The media type of the response content being sent to the client. Supported: `application/json`
fitbit-rate-limit-limit	The quota number of calls.
fitbit-rate-limit-remaining	The number of calls remaining before hitting the rate limit.
fitbit-rate-limit-reset	The number of seconds until the rate limit resets.

Note: The rate limit headers are approximate and asynchronously updated. This means that there may be a minor delay in the decrementing of remaining requests. This could result in your application receiving an unexpected 429 response if you don't track the total number of requests you make yourself.

Response Type

HTTP Status Code	HTTP response code. List of codes are found in the Troubleshooting Guide.
Status Message	Description of the status code.
Response Body	Contains the JSON response to the API call. When errors are returned by the API call, the errorType, fieldName and message text will provide more information to the cause of the failure.

Response Codes

200	A successful request.
400	The request had bad syntax or was inherently impossible to be satisfied.
401	The request requires user authentication.

Note: For a complete list of response codes, please refer to the Troubleshooting Guide.

Additional Information

Collecting Blood Glucose data

Blood Glucose data can be manually logged by the user through the Fitbit mobile app or through a 3P device. For instructions on using the blood glucose feature in the mobile app, see How do I log health information in the Fitbit App?.

Device compatibility

None of the Fitbit devices can record blood glucose data. You'll need to use a 3P device. For instructions on connecting a 3P device to collect blood glucose data, see How do I log health information in the Fitbit App?.

Rate limit

The Blood Glucose endpoints are bound by our standard rate limit. See Rate Limits.

Subscription Support for Blood Glucose

Blood Glucose does not support subscription notifications (webhooks). We recommend querying Blood Glucose data once or twice a day to determine if new data is available (e.g. 12 noon and midnight). However, the frequency or rate at which you query Blood Glucose data should be based on your specific use cases and with this in mind.

User ID not supported

Unlike the other endpoints, the Get Blood Glucose by Interval endpoint does not support the encoded user ID included in the endpoint syntax. It only supports using the "-" (dash) for the current logged-in user. When specifying the "-" (dash), the endpoint will use the access token to determine which user's data to query.