Secretin and Autism Ranking:

Current Research

Description of Studies

We have identified 21* articles published in English-language, peer-reviewed journals which evaluated the efficacy of secretin as an intervention for autistic people.  One of those articles (Honomichl et al, 2002) was a follow up study using the participants from two of the other studies.

The articles we identified included more than seven hundred autistic individuals aged from two years to 42 years old, although the bulk of studies were of primary school-age children.  Individuals with specific diagnoses included people with autistic disorder or pervasive developmental disorder - not otherwise specified.  

In most cases, the participants received a single injection of secretin and/or a single injection of a placebo (usually a saline solution). In some cases, the participants received two or three injections of secretin and/or a placebo, each dose separated by several weeks. 

The majority of participants who were injected received doses of 2 CU per KG of their body weight, although a minority received doses of 3 or 4 CU per KG of their body weight.

In one study, the participants were treated with an ointment containing secretin once-daily over four weeks. In one study, the participants received a homeopathic dose of secretin twice-daily over a period of 12 weeks.

In 10 studies, the participants received porcine secretin (derived from pigs) and in six studies the participants received synthetic human secretin. In one of these studies, porcine secretin was compared to synthetic human secretin. In the remaining studies, the type of secretin was not specified.

16 of the studies used a randomised controlled design (comparing secretin with something else) and four of the studies used a single-case design (not comparing secretin with anything else). 11 of the randomised controlled studies used a crossover design (where each participant received both secretin and placebo but at different times). 

Outcomes of Studies

• 17 of the studies reported that secretin produced no benefits or produced short-term effects that were no different to the effects produced by a placebo. 
• Five of the studies reported limited or mixed results. For example, the study by Kern et al (2002) reported that there were no significant differences between the secretin group and the placebo group on most outcome measures.
• Those five studies did report that there was a subgroup of participants with gastrointestinal problems who appeared to improve on measures such as irritability, agitation and crying when given secretin. However those benefits failed to reach statistical significance, meaning that they could have happened as the result of chance.  
• Only one of the studies (Horvath et al, 1998) reported positive benefits of secretin with no qualifications. The study recorded that “significant amelioration of the children was observed, as was a dramatic improvement in their behavior, manifested by improved eye contact, alertness, and expansion of expressive language.”
• A number of the studies reported adverse effects. For example one study (Kern et al, 2002) reported that one boy became much worse after receiving the secretin “according to his parents (e.g., tantrums, not following instructions, screaming, hyperactive, and aggression).”

Updated

16 Jun 2022

Last Review

01 Dec 2018

Next Review

01 Aug 2024