diff --git a/httpcore5-testing/src/test/java/org/apache/hc/core5/http/message/MessageSupportBenchmark.java b/httpcore5-testing/src/test/java/org/apache/hc/core5/http/message/MessageSupportBenchmark.java
new file mode 100644
index 000000000..fa758cae0
--- /dev/null
+++ b/httpcore5-testing/src/test/java/org/apache/hc/core5/http/message/MessageSupportBenchmark.java
@@ -0,0 +1,368 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package org.apache.hc.core5.http.message;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.RandomAccess;
+import java.util.concurrent.TimeUnit;
+import java.util.function.UnaryOperator;
+
+import org.apache.hc.core5.http.HeaderElement;
+import org.apache.hc.core5.http.NameValuePair;
+import org.apache.hc.core5.util.Args;
+import org.apache.hc.core5.util.CharArrayBuffer;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Warmup(iterations = 5, time = 1)
+@Measurement(iterations = 8, time = 1)
+@Fork(3)
+public class MessageSupportBenchmark {
+
+    @State(Scope.Thread)
+    public static class FormatState {
+
+        @Param({"array", "linked"})
+        public String listType;
+
+        @Param({"4", "8", "16", "32", "64", "256"})
+        public int entryCount;
+
+        private List<String> tokens;
+        private List<HeaderElement> elements;
+        private List<NameValuePair> parameters;
+        private CharArrayBuffer tokenBuffer;
+        private CharArrayBuffer elementBuffer;
+        private CharArrayBuffer parameterBuffer;
+
+        @Setup
+        public void setup() {
+            final List<String> tokenValues = new ArrayList<>(entryCount);
+            final List<HeaderElement> elementValues = new ArrayList<>(entryCount);
+            final List<NameValuePair> parameterValues = new ArrayList<>(entryCount);
+
+            for (int i = 0; i < entryCount; i++) {
+                tokenValues.add("token-" + i);
+                elementValues.add(new BasicHeaderElement("element-" + i, "value-" + i));
+                parameterValues.add(new BasicNameValuePair("param-" + i, "value-" + i));
+            }
+
+            if ("linked".equals(listType)) {
+                tokens = new LinkedList<>(tokenValues);
+                elements = new LinkedList<>(elementValues);
+                parameters = new LinkedList<>(parameterValues);
+            } else {
+                tokens = tokenValues;
+                elements = elementValues;
+                parameters = parameterValues;
+            }
+
+            final int capacity = entryCount * 32 + 64;
+            tokenBuffer = new CharArrayBuffer(capacity);
+            elementBuffer = new CharArrayBuffer(capacity);
+            parameterBuffer = new CharArrayBuffer(capacity);
+        }
+
+    }
+
+    @Benchmark
+    public int formatTokensIndexed(final FormatState state) {
+        state.tokenBuffer.clear();
+        formatTokensIndexed(state.tokenBuffer, state.tokens, null);
+        return state.tokenBuffer.length();
+    }
+
+    @Benchmark
+    public int formatTokensIterator(final FormatState state) {
+        state.tokenBuffer.clear();
+        formatTokensIterator(state.tokenBuffer, state.tokens, null);
+        return state.tokenBuffer.length();
+    }
+
+    @Benchmark
+    public int formatTokensAdaptive(final FormatState state) {
+        state.tokenBuffer.clear();
+        formatTokensAdaptive(state.tokenBuffer, state.tokens, null);
+        return state.tokenBuffer.length();
+    }
+
+    @Benchmark
+    public int formatElementsIndexed(final FormatState state) {
+        state.elementBuffer.clear();
+        formatElementsIndexed(state.elementBuffer, state.elements);
+        return state.elementBuffer.length();
+    }
+
+    @Benchmark
+    public int formatElementsIterator(final FormatState state) {
+        state.elementBuffer.clear();
+        formatElementsIterator(state.elementBuffer, state.elements);
+        return state.elementBuffer.length();
+    }
+
+    @Benchmark
+    public int formatElementsAdaptive(final FormatState state) {
+        state.elementBuffer.clear();
+        formatElementsAdaptive(state.elementBuffer, state.elements);
+        return state.elementBuffer.length();
+    }
+
+    @Benchmark
+    public int formatParametersIndexed(final FormatState state) {
+        state.parameterBuffer.clear();
+        formatParametersIndexed(state.parameterBuffer, state.parameters);
+        return state.parameterBuffer.length();
+    }
+
+    @Benchmark
+    public int formatParametersIterator(final FormatState state) {
+        state.parameterBuffer.clear();
+        formatParametersIterator(state.parameterBuffer, state.parameters);
+        return state.parameterBuffer.length();
+    }
+
+    @Benchmark
+    public int formatParametersAdaptive(final FormatState state) {
+        state.parameterBuffer.clear();
+        formatParametersAdaptive(state.parameterBuffer, state.parameters);
+        return state.parameterBuffer.length();
+    }
+
+    private static void formatTokensIndexed(
+            final CharArrayBuffer dst,
+            final List<String> tokens,
+            final UnaryOperator<String> transformation) {
+        Args.notNull(dst, "Destination");
+        if (tokens == null) {
+            return;
+        }
+        for (int i = 0; i < tokens.size(); i++) {
+            final String token = tokens.get(i);
+            final String element = transformation != null ? transformation.apply(token) : token;
+            if (i > 0) {
+                dst.append(", ");
+            }
+            dst.append(element);
+        }
+    }
+
+    private static void formatTokensIterator(
+            final CharArrayBuffer dst,
+            final List<String> tokens,
+            final UnaryOperator<String> transformation) {
+        Args.notNull(dst, "Destination");
+        if (tokens == null) {
+            return;
+        }
+        final Iterator<String> iterator = tokens.iterator();
+        boolean first = true;
+        while (iterator.hasNext()) {
+            final String token = iterator.next();
+            final String element = transformation != null ? transformation.apply(token) : token;
+            if (!first) {
+                dst.append(", ");
+            }
+            dst.append(element);
+            first = false;
+        }
+    }
+
+    private static void formatTokensAdaptive(
+            final CharArrayBuffer dst,
+            final List<String> tokens,
+            final UnaryOperator<String> transformation) {
+        Args.notNull(dst, "Destination");
+        if (tokens == null) {
+            return;
+        }
+        if (tokens instanceof RandomAccess) {
+            for (int i = 0; i < tokens.size(); i++) {
+                final String token = tokens.get(i);
+                final String element = transformation != null ? transformation.apply(token) : token;
+                if (i > 0) {
+                    dst.append(", ");
+                }
+                dst.append(element);
+            }
+        } else {
+            final Iterator<String> iterator = tokens.iterator();
+            boolean first = true;
+            while (iterator.hasNext()) {
+                final String token = iterator.next();
+                final String element = transformation != null ? transformation.apply(token) : token;
+                if (!first) {
+                    dst.append(", ");
+                }
+                dst.append(element);
+                first = false;
+            }
+        }
+    }
+
+    private static void formatElementsIndexed(
+            final CharArrayBuffer dst,
+            final List<HeaderElement> elements) {
+        Args.notNull(dst, "Destination");
+        if (elements == null) {
+            return;
+        }
+        for (int i = 0; i < elements.size(); i++) {
+            final HeaderElement element = elements.get(i);
+            if (i > 0) {
+                dst.append(", ");
+            }
+            BasicHeaderValueFormatter.INSTANCE.formatHeaderElement(dst, element, false);
+        }
+    }
+
+    private static void formatElementsIterator(
+            final CharArrayBuffer dst,
+            final List<HeaderElement> elements) {
+        Args.notNull(dst, "Destination");
+        if (elements == null) {
+            return;
+        }
+        final Iterator<HeaderElement> iterator = elements.iterator();
+        boolean first = true;
+        while (iterator.hasNext()) {
+            final HeaderElement element = iterator.next();
+            if (!first) {
+                dst.append(", ");
+            }
+            BasicHeaderValueFormatter.INSTANCE.formatHeaderElement(dst, element, false);
+            first = false;
+        }
+    }
+
+    private static void formatElementsAdaptive(
+            final CharArrayBuffer dst,
+            final List<HeaderElement> elements) {
+        Args.notNull(dst, "Destination");
+        if (elements == null) {
+            return;
+        }
+        if (elements instanceof RandomAccess) {
+            for (int i = 0; i < elements.size(); i++) {
+                final HeaderElement element = elements.get(i);
+                if (i > 0) {
+                    dst.append(", ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatHeaderElement(dst, element, false);
+            }
+        } else {
+            final Iterator<HeaderElement> iterator = elements.iterator();
+            boolean first = true;
+            while (iterator.hasNext()) {
+                final HeaderElement element = iterator.next();
+                if (!first) {
+                    dst.append(", ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatHeaderElement(dst, element, false);
+                first = false;
+            }
+        }
+    }
+
+    private static void formatParametersIndexed(
+            final CharArrayBuffer dst,
+            final List<NameValuePair> params) {
+        Args.notNull(dst, "Destination");
+        if (params == null) {
+            return;
+        }
+        for (int i = 0; i < params.size(); i++) {
+            final NameValuePair param = params.get(i);
+            if (i > 0) {
+                dst.append("; ");
+            }
+            BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(dst, param, false);
+        }
+    }
+
+    private static void formatParametersIterator(
+            final CharArrayBuffer dst,
+            final List<NameValuePair> params) {
+        Args.notNull(dst, "Destination");
+        if (params == null) {
+            return;
+        }
+        final Iterator<NameValuePair> iterator = params.iterator();
+        boolean first = true;
+        while (iterator.hasNext()) {
+            final NameValuePair param = iterator.next();
+            if (!first) {
+                dst.append("; ");
+            }
+            BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(dst, param, false);
+            first = false;
+        }
+    }
+
+    private static void formatParametersAdaptive(
+            final CharArrayBuffer dst,
+            final List<NameValuePair> params) {
+        Args.notNull(dst, "Destination");
+        if (params == null) {
+            return;
+        }
+        if (params instanceof RandomAccess) {
+            for (int i = 0; i < params.size(); i++) {
+                final NameValuePair param = params.get(i);
+                if (i > 0) {
+                    dst.append("; ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(dst, param, false);
+            }
+        } else {
+            final Iterator<NameValuePair> iterator = params.iterator();
+            boolean first = true;
+            while (iterator.hasNext()) {
+                final NameValuePair param = iterator.next();
+                if (!first) {
+                    dst.append("; ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(dst, param, false);
+                first = false;
+            }
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/httpcore5/src/main/java/org/apache/hc/core5/http/message/MessageSupport.java b/httpcore5/src/main/java/org/apache/hc/core5/http/message/MessageSupport.java
index 71640401e..55acd6fa8 100644
--- a/httpcore5/src/main/java/org/apache/hc/core5/http/message/MessageSupport.java
+++ b/httpcore5/src/main/java/org/apache/hc/core5/http/message/MessageSupport.java
@@ -33,6 +33,7 @@
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.RandomAccess;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.function.BiConsumer;
@@ -80,12 +81,27 @@ public static void formatTokens(final CharArrayBuffer dst, final List<String> to
         if (tokens == null) {
             return;
         }
-        for (int i = 0; i < tokens.size(); i++) {
-            final String element = transformation != null ? transformation.apply(tokens.get(i)) : tokens.get(i);
-            if (i > 0) {
-                dst.append(", ");
+        if (tokens instanceof RandomAccess) {
+            for (int i = 0; i < tokens.size(); i++) {
+                final String token = tokens.get(i);
+                final String element = transformation != null ? transformation.apply(token) : token;
+                if (i > 0) {
+                    dst.append(", ");
+                }
+                dst.append(element);
+            }
+        } else {
+            final Iterator<String> iterator = tokens.iterator();
+            boolean first = true;
+            while (iterator.hasNext()) {
+                final String token = iterator.next();
+                final String element = transformation != null ? transformation.apply(token) : token;
+                if (!first) {
+                    dst.append(", ");
+                }
+                dst.append(element);
+                first = false;
             }
-            dst.append(element);
         }
     }
 
@@ -446,12 +462,25 @@ public static void formatElements(final CharArrayBuffer dst, final List<HeaderEl
         if (elements == null) {
             return;
         }
-        for (int i = 0; i < elements.size(); i++) {
-            final HeaderElement element = elements.get(i);
-            if (i > 0) {
-                dst.append(", ");
+        if (elements instanceof RandomAccess) {
+            for (int i = 0; i < elements.size(); i++) {
+                final HeaderElement element = elements.get(i);
+                if (i > 0) {
+                    dst.append(", ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatHeaderElement(dst, element, false);
+            }
+        } else {
+            final Iterator<HeaderElement> iterator = elements.iterator();
+            boolean first = true;
+            while (iterator.hasNext()) {
+                final HeaderElement element = iterator.next();
+                if (!first) {
+                    dst.append(", ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatHeaderElement(dst, element, false);
+                first = false;
             }
-            BasicHeaderValueFormatter.INSTANCE.formatHeaderElement(dst, element, false);
         }
     }
 
@@ -550,12 +579,25 @@ public static void formatParameters(final CharArrayBuffer dst, final List<NameVa
         if (params == null) {
             return;
         }
-        for (int i = 0; i < params.size(); i++) {
-            final NameValuePair param = params.get(i);
-            if (i > 0) {
-                dst.append("; ");
+        if (params instanceof RandomAccess) {
+            for (int i = 0; i < params.size(); i++) {
+                final NameValuePair param = params.get(i);
+                if (i > 0) {
+                    dst.append("; ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(dst, param, false);
+            }
+        } else {
+            final Iterator<NameValuePair> iterator = params.iterator();
+            boolean first = true;
+            while (iterator.hasNext()) {
+                final NameValuePair param = iterator.next();
+                if (!first) {
+                    dst.append("; ");
+                }
+                BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(dst, param, false);
+                first = false;
             }
-            BasicHeaderValueFormatter.INSTANCE.formatNameValuePair(dst, param, false);
         }
     }