Echinacea for colds and flu

Echinacea purpurea or purple coneflower can strengthen the immune system and thus ensure that colds, flu and some infectious diseases occur less often or heal more quickly. The problem with natural remedies is the variable quality of the plants and their products. Standardizing can provide a solution to that problem. The effectiveness of echinacea in the prevention or treatment of upper respiratory tract infections (common cold) has been investigated in many studies. The results of these studies are not consistent. In most cases, positive results concern the treatment of colds at an early stage rather than its prevention. One problem is that many different available preparations have been used, the composition of which is not clear.

Active substances

Checking and standardizing plants and preparations for their active substances can improve quality. In Echinacea, it is mainly alkylamides, polysaccharides and chicory acid that play an important role in stimulating the immune system. The different substances each have their own effect and complement each other’s activity. The guaranteed presence of these three groups of substances in effective quantities determines the effectiveness of echinacea preparations.

Effect of respiratory infections

A study with a standardized echinacea preparation demonstrated effectiveness in infections of the upper respiratory tract. It reduces the duration and severity of the disease. When taken immediately at the first symptoms of a viral infection (chills, fever, muscle aches, headache, sore throat, cough or nasal congestion), echinacea could prevent the further development of the infection. Echinacea can also be used preventively to prevent infections, for example during the flu season. The elderly and top athletes such as runners and cyclists are more vulnerable to an upper respiratory infection. People with a public function have a greater chance of being infected by carriers of a cold or flu virus.

A study with a standardized preparation

A Canadian echinacea preparation ECP is standardized for effective concentrations of the active substances. These concentrations have been calculated based on the results of experimental research with immune cells and laboratory animals, which examined the dose-response relationship for immune stimulation2,3. ECP contains 0.052 mg/ml alkylamides, 5.6 mg/ml polysaccharides and 0.72 mg/ml chicory acid.
This study included 282 people (18-65 years) who had multiple upper respiratory tract infections in the past year. The subjects took the echinacea extract or a placebo for seven days as soon as symptoms of infection occurred. The prescribed dosage was 10 doses for the first day and 4 doses for the remaining 6 days. The nature and severity of the symptoms were recorded by the participants themselves every day on a 10-point rating scale. A research assistant (a specially trained nurse) examined the participants on the 3rd and 8th day of their cold and also checked for additional infections, such as sinusitis, ear infections, or pneumonia.

The results with Echinacea

A total of 128 participants caught a cold, 59 in the echinacea group and 69 in the placebo group. The symptom score was 23.1% lower in the echinacea group than in the placebo group. The symptoms on the score list were runny nose, sore throat, nasal congestion, cough, fatigue, headache and sneezing. The scores for symptoms that most interfere with daily activities were significantly lower in the echinacea group: 31% lower for fatigue, 39% lower for headache and 44% lower for chills. The researchers’ scores corresponded with the participants’ scores and thus confirmed the beneficial effect of the echinacea preparation on reducing and shortening the disease symptoms. Furthermore, bronchitis occurred in two participants in the echinacea group and five in the placebo group. By the fourth day, half of the participants in the echinacea group had their symptom scores reduced by 50%. In the placebo group this happened after 5½ days. On the seventh day, 95% of the echinacea group had recovered compared to 63% of the placebo group. The duration of the disease was 1½ days shorter in the echinacea group. This is comparable to what can be achieved with regular anti-flu medications.


A good echinacea preparation can strengthen the immune system and thus prevent infections or heal them faster. People with an allergy to plants of the Composite family (Asteraceae), such as arnica, calendula, dandelion, should not use echinacea preparations.

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