Summary of Council decision:

Two issues were investigated, both of which were Upheld.

Ad description

A leaflet promoting Active Iron, an iron supplement, seen in December 2017, featured text stating "9/10 find Active Iron better tolerated*". Small text linked by an asterisk stated "Data on file, user reported tolerability survey, age 39 + 10 years, 78% female, n = 389".


The complainant challenged whether:

1. the claim "9/10 find Active Iron better tolerated" was misleading and could be substantiated; and

2. the same claim was verifiable.


1. Solvotrin Therapeutics Ltd stated that the claim did not specifically compare Active Iron with ferrous sulphate 200 mg (65 mg elemental iron), as understood by the complainant. They stated that nothing in the ad suggested that the product was being compared with high-dose formulas.

They stated that the reference linked to the claim was incorrect, and the supporting reference was actually “Data on file, user tolerability, age 43 +-10 years, 83% female, n=101”. This referred to a tolerability report, which gathered data from 116 respondents, 101 of whom had previously taken oral iron products, about their experiences taking previous supplements as well as Active Iron. Thirty-five of the respondents had previously taken low dose products (30 mg or less of elemental iron), which Solvotrin Therapeutics considered to be comparable products to Active Iron. They said that most of those respondents had taken a product that had an even lower dose than Active Iron. Those participants experienced better tolerability on Active Iron compared to their previous product, with little or no reported side effects. While the full report included data from respondents on a higher dose formula, the claim in the ad related specifically to those 35 respondents on low dose formulas, which they believed to be a representative figure for tolerability purposes. They referred to UK Government Guidelines on Acceptability Studies from the Advisory Committee on Borderline Substances in the UK, which stated that acceptability studies must be run for at least one week and with at least 15 participants. Solvotrin Therapeutics also provided a published clinical report on Active Iron, which they said potentially demonstrated a better explanation for the tolerability of the product, due to reduced toxicity and reactive oxygen species (ROS) in gut cells. Based on that evidence, they believed that the claim had been substantiated and was not misleading.

2. Solvotrin Therapeutics said they did not accept that the claim was a comparison with an identifiable competitor, as there were a large number of comparable low dose oral iron supplements on the market and it was not possible to identify individual competitors based on the comparisons. However, they believed the comparison was verifiable because there was well-documented evidence of the side effects of oral iron supplementation generally, and those were widely known. They provided seven additional studies.


1. Upheld

The claim stated "9/10 find Active Iron better tolerated". Beneath that were two charts, showing the percentage of individuals who had experienced a variety of different gastrointestinal side effects when taking Active Iron and “Other Iron Products”. Due to the lack of any further information about the specific iron products being compared against, we considered that consumers would interpret the claim "9/10 find Active Iron better tolerated" to mean that nine out of ten people would experience fewer gastrointestinal side effects when taking Active Iron as opposed to any other iron supplement. The nutritional information section of the leaflet stated “Active Iron is suitable for children over 12 years old, including pregnant women and the elderly” and the leaflet referred to a number of different symptoms of low iron, benefits of taking iron supplements, and various groups who could benefit from taking such supplements. In that context, we considered that consumers would understand that the supplement was intended for general use by otherwise healthy individuals over 12 years old, and had been proven to be better tolerated in that group.

The leaflet also featured the claim “Clinically proven better tolerated”, and we considered that reinforced the impression that the reduction of side effects when taking Active Iron was substantiated by clinical evidence. In order to substantiate the claim as consumers were likely to understand it, we expected to see adequately-controlled, blinded, randomised clinical trials comparing the effects of Active Iron with those of other iron supplements on the market.

We assessed the evidence submitted by Solvotrin Therapeutics. The consumer tolerability survey measured the level of reported side effects from Active Iron compared to those experienced with a previous iron supplement. While the report differentiated between those participants who had previously taken “low dose” and “high dose” iron products, no further details were provided regarding the exact doses and/or products used. In addition, despite Solvotrin Therapeutics’ assertion to the contrary, we understood that the nine out of ten figure was based on the sub-group of all participants who had ever previously taken an iron supplement, rather than those who had only taken low doses. We noted that participants were being asked to recall symptoms retrospectively. No information, however, was given about how long ago they had taken their previous supplements, or how long they had taken them for. While we understood that the questionnaire used was based on one that was discussed in another paper submitted by the advertiser, no further details were provided of how symptoms were assessed, or any explanation of how the method was appropriate in a retrospective consumer survey context as opposed to a clinical setting. As there was no control, blinding of participants to minimise bias was not possible. We further noted that participants were predominantly middle-aged females, while the context of the leaflet implied that improved tolerance had been proven in a wider population. Overall, regardless of the uncertainties regarding methodology, we considered that results of a consumer survey were inadequate to substantiate the claim as consumers were likely to understand it.

A clinical trial compared iron absorption from iron-natured whey protein (the delivery mechanism used in Active Iron) and a dose of 25 mg elemental iron, demonstrating that iron-natured whey protein was better absorbed. However, the study’s authors acknowledged that it did not have sufficient power to evaluate gastrointestinal tolerability, and that further research was needed with higher iron doses, longer follow-up, and in different populations. The paper also presented results of an in vitro study suggesting reduced ROS and toxicity in gut cells when using iron-natured whey protein. However, we considered that in vitro studies were insufficient on their own to demonstrate that effect of the product in humans.

Solvotrin Therapeutics also submitted several meta-analyses on the gastrointestinal tolerability of ferrous sulphate and other forms of iron supplement, and a randomised controlled trial on the gastrointestinal effects of iron-fortified food on infants. However, none of these related to the form of iron used in Active Iron and were not relevant to substantiating a comparison between Active Iron and other iron products. Additional papers discussed the physiological processes of iron absorption in the body and a questionnaire for the assessment of side effects in patients.

In the absence of adequately-controlled and significant clinical evidence showing that nine out of ten people would experience fewer gastrointestinal symptoms when taking Active Iron compared to other iron products, we concluded that the claim had not been substantiated and was therefore misleading.

On that point, the ad breached CAP Code (Edition 12) rules  3.1 3.1 Marketing communications must not materially mislead or be likely to do so.  (Misleading advertising),  3.7 3.7 Before distributing or submitting a marketing communication for publication, marketers must hold documentary evidence to prove claims that consumers are likely to regard as objective and that are capable of objective substantiation. The ASA may regard claims as misleading in the absence of adequate substantiation.  (Substantiation) and  3.33 3.33 Marketing communications that include a comparison with an identifiable competitor must not mislead, or be likely to mislead, the consumer about either the advertised product or the competing product.  (Comparisons with identifiable competitors).

2. Upheld

The CAP Code required comparisons with identifiable competitors to be verifiable. That meant that an ad which featured a comparison with an identifiable competitor or competitors needed to include, or direct a consumer to, sufficient information to allow them to understand the comparison, and be able to check the claims were accurate.

We understood that three of the references in the small print on the leaflet had been included in error and were not intended as sources for the claim "9/10 find Active Iron better tolerated". We acknowledged Solvotrin Therapeutics’ assertion that they would amend this in future, and that the correct reference was “Data on file, user tolerability, age 43 +-10 years, 83% female, n=101”. However, the range of references included in the original ad, and lack of clarity over which claims they were linked to, in themselves meant that consumers would be incapable of verifying the claim.

We considered that in order to understand the basis of the comparison, consumers would need details of the specific supplements Active Iron was being compared against. The ad referred generally to “other iron products”, and that information was not provided or signposted. The small print did not make clear that the claim was based on the results of a consumer survey, as opposed to a clinical trial. Furthermore, we noted that the survey results themselves were not in the public domain and therefore could not be accessed by consumers to allow them to obtain that information themselves. Notwithstanding that we considered that the survey was not sufficient evidence to substantiate the comparative claim, we also considered that it wasn’t verifiable.

On that point, the ad breached CAP Code (Edition 12) rule  3.35 3.35 They must objectively compare one or more material, relevant, verifiable and representative feature of those products, which may include price.  (Comparisons with identifiable competitors).


The ad must not appear again the form complained about. We told Solvotrin Therapeutics Ltd to ensure they held adequate evidence to substantiate comparative claims made in their advertising. We also told them to ensure those claims were verifiable.

CAP Code (Edition 12)

3.1     3.33     3.35     3.7    

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