diff --git a/Sources/LoopAlgorithm/Glucose/GlucoseMath.swift b/Sources/LoopAlgorithm/Glucose/GlucoseMath.swift
index 9987980..444e977 100644
--- a/Sources/LoopAlgorithm/Glucose/GlucoseMath.swift
+++ b/Sources/LoopAlgorithm/Glucose/GlucoseMath.swift
@@ -79,6 +79,10 @@ extension BidirectionalCollection where Element: GlucoseSampleValue, Index == In
     ///   - gradualTransitionThreshold: Maximum allowed difference between consecutive readings in mg/dL (default 40.0)
     /// - Returns: True if all consecutive differences are within the threshold
     public func hasGradualTransitions(gradualTransitionThreshold: Double = 40.0) -> Bool {
+        if contains(where: \.wasUserEntered) {
+            return filter { !$0.wasUserEntered }.hasGradualTransitions(gradualTransitionThreshold: gradualTransitionThreshold)
+        }
+
         guard count > 1 else {
             return false  // A single point could be a spike and should not be used for momentum calculation
         }
@@ -114,6 +118,10 @@ extension BidirectionalCollection where Element: GlucoseSampleValue, Index == In
         velocityMaximum: LoopQuantity? = nil
     ) -> [GlucoseEffect] {
 
+        if contains(where: \.wasUserEntered) {
+            return filter { !$0.wasUserEntered }.linearMomentumEffect(duration: duration, delta: delta, velocityMaximum: velocityMaximum)
+        }
+
         let velocityMax = velocityMaximum ?? LoopQuantity(unit: .milligramsPerDeciliterPerMinute, doubleValue: 4.0)
 
         guard
@@ -176,6 +184,11 @@ extension Collection where Element: GlucoseSampleValue, Index == Int {
     /// - Parameter effects: Glucose effects to be countered, in chronological order
     /// - Returns: An array of velocities describing the change in glucose samples compared to the specified effects
     public func counteractionEffects(to effects: [GlucoseEffect]) -> [GlucoseEffectVelocity] {
+        // A manual entry is a different measurement from the CGM; a change between the two is not glucose movement.
+        if contains(where: \.wasUserEntered) {
+            return filter { !$0.wasUserEntered }.counteractionEffects(to: effects)
+        }
+
         let mgdL = LoopUnit.milligramsPerDeciliter
         let velocityUnit = GlucoseEffectVelocity.perSecondUnit
         var velocities = [GlucoseEffectVelocity]()
diff --git a/Tests/LoopAlgorithmTests/GlucoseMathTests.swift b/Tests/LoopAlgorithmTests/GlucoseMathTests.swift
index ee346ba..8cb1a4f 100644
--- a/Tests/LoopAlgorithmTests/GlucoseMathTests.swift
+++ b/Tests/LoopAlgorithmTests/GlucoseMathTests.swift
@@ -422,6 +422,52 @@ final class GlucoseMathTests: XCTestCase {
         }
     }
 
+    private func manualEntry(at date: Date, mgdl: Double) -> GlucoseFixtureValue {
+        GlucoseFixtureValue(
+            startDate: date,
+            quantity: LoopQuantity(unit: .milligramsPerDeciliter, doubleValue: mgdl),
+            isDisplayOnly: false,
+            wasUserEntered: true,
+            provenanceIdentifier: nil,
+            condition: nil,
+            trendRate: nil
+        )
+    }
+
+    func testMomentumEffectIgnoresManualEntry() {
+        var input = loadInputFixture("momentum_effect_falling_glucose_input")
+        let expected = input.linearMomentumEffect(duration: .minutes(30))
+        let middle = input[input.count / 2]
+        input.insert(manualEntry(at: middle.startDate.addingTimeInterval(.minutes(2.5)), mgdl: middle.quantity.doubleValue(for: .milligramsPerDeciliter) - 30), at: input.count / 2 + 1)
+
+        XCTAssertEqual(expected, input.linearMomentumEffect(duration: .minutes(30)))
+    }
+
+    func testCounteractionEffectsIgnoreManualEntry() {
+        var input = loadInputFixture("counteraction_effect_falling_glucose_input")
+        let insulinEffect = loadOutputFixture("counteraction_effect_falling_glucose_insulin")
+        let expected = input.counteractionEffects(to: insulinEffect)
+        let index = input.count / 2
+        let sample = input[index]
+        input.insert(manualEntry(at: sample.startDate.addingTimeInterval(.minutes(4.5)), mgdl: sample.quantity.doubleValue(for: .milligramsPerDeciliter) - 30), at: index + 1)
+
+        let effects = input.counteractionEffects(to: insulinEffect)
+        let unit = GlucoseEffectVelocity.perSecondUnit
+
+        XCTAssertEqual(expected.map(\.startDate), effects.map(\.startDate))
+        XCTAssertEqual(expected.map(\.endDate), effects.map(\.endDate))
+        XCTAssertEqual(expected.map { $0.quantity.doubleValue(for: unit) }, effects.map { $0.quantity.doubleValue(for: unit) })
+    }
+
+    func testGradualTransitionsIgnoreManualEntry() {
+        var input = loadInputFixture("momentum_effect_falling_glucose_input")
+        XCTAssertTrue(input.hasGradualTransitions())
+        let middle = input[input.count / 2]
+        input.insert(manualEntry(at: middle.startDate.addingTimeInterval(.minutes(2.5)), mgdl: middle.quantity.doubleValue(for: .milligramsPerDeciliter) + 60), at: input.count / 2 + 1)
+
+        XCTAssertTrue(input.hasGradualTransitions())
+    }
+
     func testCounteractionEffectsForNoGlucose() {
         let input = [GlucoseFixtureValue]()
         let insulinEffect = loadOutputFixture("counteraction_effect_falling_glucose_insulin")