Sponsorship Disclosure on Instagram: A Systematic Review of Research from 2020 to 2025 ()
1. Introduction
Digital advertising has undergone a profound transformation with the emergence of Social Media Influencers (SMIs). What began as a marginal practice has developed into a global, multi-billion-dollar industry (Libai et al., 2025). This rapid growth is driven by the unique relationships influencers build with their audiences, marked by authenticity and relatability that traditional celebrity endorsements often lack (Liu & Zheng, 2024). At the same time, the overlap between personal expression and commercial promotion has raised ethical and regulatory concerns, as the boundary between content and advertising becomes increasingly indistinct. At the center of these debates lies the issue of sponsorship disclosure (Van Der Goot et al., 2021).
Regulatory agencies in the United States, Europe, and other regions require influencers to disclose sponsored content to promote transparency and safeguard consumers against misleading marketing practices (Musiyiwa & Jacobson, 2023; Van Reijmersdal et al., 2023). Despite these mandates, the effectiveness of disclosures remains contested in the academic literature. Some studies show that disclosures activate consumers’ persuasion knowledge, prompting skepticism and reducing brand favorability, while others suggest disclosures have negligible effects or, in some cases, foster greater trust and strengthen purchase intentions (Liu et al., 2024; Sesar et al., 2022).
This review synthesizes research and offers an integrated perspective on influencer sponsorship disclosure published between 2020 and 2025 for clarification of these divergent findings. Drawing on evidence from field studies, controlled experiments, and qualitative investigations, the paper argues that the consequences of disclosure cannot be reduced to a binary outcome. Instead, they depend on a complex interaction of psychological, contextual, and behavioral factors that shape consumer responses.
Research Q1: How do sponsorship disclosures in SMI marketing shape consumer responses across psychological mechanisms, message characteristics, audience factors, and platform contexts, and under what conditions do these disclosures generate short-term costs versus long-term benefits?
2. Methodology
The literature search was conducted using the keywords “social media influencer sponsorship disclosure”, which were identified as central to the research topic. These terms were applied to Google Scholar. The initial search yielded 236 publications. To maintain both topicality and relevance, the review was restricted to studies published between 2020 and 2025. Following the removal of duplicates and the exclusion of records not available in full-text PDF format, the dataset was reduced to 165 articles. A final selection of 37 articles was made after a careful screening of titles and abstracts during the data extraction stage. To ensure methodological transparency and coding consistency, inter-coder reliability was tested.
Two researchers independently coded a random subset of 10 articles (about 27% of the total sample) using a predefined framework that covered dimensions such as study design, disclosure type, theoretical foundation, and key outcomes. The resulting Cohen’s Kappa (κ = 0.78) reflected a substantial level of agreement across categorical codes including Methodology Type and Key Moderator. Any differences in coding were reviewed and resolved through discussion, leading to a reliable and consistent final dataset. The rigorous, systematic nature of this selection process is visually documented in the PRISMA flow chart in Figure 1. Additionally, an overview of the sample is provided in Table 1.
Figure 1. PRISMA flow chart: article screening and selection process.
Table 1. List of journal articles on social media influencers’ sponsorship disclosure between 2020 and 2025.
Year |
Article Title 32 |
Journal Name |
Keywords |
2020 |
# Sponsored! How the recognition of sponsoring on Instagram posts affects adolescents’ brand evaluations through source evaluations |
Computers in Human Behavior |
N/A |
2020 |
The effects of the standardized Instagram disclosure for micro-and meso-influencers |
Computers in Human Behavior |
Influencer marketing; Instagram; Disclosure; Persuasion knowledge; Parasocial interaction; Online behavior |
2020 |
# sponsored: Consumer insights on social media influencer marketing |
Public Relations Inquiry |
Marketing; public relations; social media; social media influencers; sponsored content; women |
2020 |
A sponsorship disclosure is not enough? How advertising literacy intervention affects consumer reactions to sponsored influencer posts |
Journal of Promotion Management |
Persuasion knowledge; advertising literacy intervention; sponsorship disclosure; Instagram; sponsored influencer posts |
2021 |
Reducing Resistance: The Impact of Nonfollowers’ and Followers’ Parasocial Relationships with Social Media Influencers on Persuasive Resistance and Advertising Effectiveness |
Human Communication Research |
Social Media Influencer, Parasocial Relationships, Source Trustworthiness; Persuasion; Counterarguing; Native Advertising |
2021 |
How social media influencers’ narrative strategies benefit cultivating influencer marketing: Tackling issues of cultural barriers, commercialised content, and sponsorship disclosure |
Journal of Business Research |
Social media influencers; Influencer marketing; Narrative strategy; Cultural barriers; Commercial content; Sponsorship disclosure |
2021 |
Influencer advertising on social media: The multiple inference model on influencer-product congruence and sponsorship disclosure |
Journal of Business Research |
Influencer advertising; Native advertising; Multiple motive inference;
Influencer-product congruence; Sponsorship disclosure; Advertising recognition |
2021 |
Living in a material world: Sponsored Instagram posts and the role of materialism, hedonic enjoyment, perceived trust, and need to belong |
Social media + Society |
sponsored content engagement; materialism; hedonic enjoyment; influencer trust; need to belong |
2021 |
Blind trust? The importance and interplay of parasocial relationships and advertising disclosures in explaining influencers’ persuasive effects on their followers |
International Journal of Advertising |
Social media influencer; parasocial relationship; source credibility; persuasion; advertising disclosure; persuasion knowledge |
2021 |
Disclosing product placement in audiovisual media services: a practical and scientific perspective on the implementation of disclosures across the European Union |
International Journal of Advertising |
Product placement; disclosures; television program; AVMSD; research; practice |
2021 |
The disclosure paradox: How persuasion knowledge mediates disclosure effects in sponsored media content |
International Journal of Advertising |
Persuasion knowledge; disclosure; sponsored content; persuasion; advertising |
2021 |
The effect of influencer–product fit on advertising recognition and the role of an enhanced disclosure in increasing sponsorship transparency |
International Journal of Advertising |
Instagram; congruency; ad recognition; sponsorship transparency; influencer marketing |
2021 |
The mechanism of social media marketing: influencer characteristics, consumer empathy, immersion, and sponsorship disclosure |
International Journal of Advertising |
Social media influencers; centrality; trustworthiness; empathy; immersion; sponsorship disclosure |
2022 |
Effect of sponsorship disclosure on online consumer responses to positive reviews: The moderating role of emotional intensity and tie strength |
Decision Support Systems |
Online reviews; Sponsorship disclosure; Emotional intensity; Tie strength; Language expectancy theory; Moderated moderation model |
2022 |
How, why, and when disclosure type matters for influencer marketing |
International Journal of Research in Marketing |
Influencer marketing; Instagram; Disclosure; Advertising transparency; Multiple product endorsement |
2022 |
Too much information: An examination of the effects of social self-disclosure embedded within influencer eWOM campaigns |
Journal of Business Research |
Influencer; Self-disclosure; Appropriateness; Sponsored; WOM; Social Media |
2022 |
Relationship between advertising disclosure, influencer credibility and purchase intention |
Journal of Risk and Financial Management |
Influencer marketing; purchase intention; brand awareness; advertising disclosure; moderation model; mediation model |
2022 |
The effects of advertisement disclosure on heavy and light Instagram users |
Electronic markets |
Advertisement disclosure; Heavy and light users; Usage intensity; Social networking site; Influencer marketing; Advertising performance |
2022 |
Are they being authentic? The effects of self-disclosure and message sidedness on sponsored post effectiveness |
International Journal of Advertising |
Influencer marketing; sponsorship;
self-disclosure; message sidedness;
influencer credibility |
2022 |
Influencers’ disclosures of advertising and responses from youth with varying levels of theory of mind |
Journal of Current Issues &Research in Advertising |
N/A |
2022 |
Social media influencers and followers: Theorization of a trans-parasocial relation and explication of its implications for influencer advertising |
Journal of advertising |
N/A |
2022 |
The effects of message type and sponsorship disclosure in influencer marketing of prescription drugs |
Journal of Global Marketing |
Direct-to-consumer advertising; influencer marketing; sponsorship disclosure; pharmaceutical advertising; prescription drug advertising |
2023 |
Can I @handle it? The effects of sponsorship disclosure in TikTok influencer marketing videos with different product integration levels on adolescents’ persuasion knowledge and brand outcomes |
Computers in Human Behavior |
Influencer marketing; Social media; TikTok; Persuasion knowledge; Adolescents; Brand outcomes |
2023 |
Show me that you are advertising: Visual salience of products attenuates detrimental effects of persuasion knowledge activation in influencer advertising |
Computers in Human Behavior |
Visual salience; Persuasion knowledge; Advertising congruence; Sponsorship disclosure; Attention; Influencer advertising |
2023 |
Sponsorship disclosure in social media influencer marketing: The algorithmic and non-algorithmic barriers |
Social Media+ Society |
sponsorship disclosure; influencer marketing; compliance; qualitative research; algorithms |
2023 |
What drives digital engagement with sponsored videos? An investigation of video influencers’ authenticity management strategies |
Journal of the Academy of Marketing Science |
Advertising Psychology; Digital Ethics; Digital Marketing; Media Education; Public Engagement with Science; Social Influence |
2023 |
Disclosure, content cues, emotions and behavioural engagement in social media influencer marketing: an exploratory
multi-stakeholder perspective |
Journal of Marketing Management |
Social media influencers; influencer marketing; disclosure; content cues; stakeholder |
2023 |
Disclosure-driven recognition of native advertising: A test of two competing mechanisms |
Journal of Interactive Advertising |
Native advertising; persuasion knowledge; sponsorship transparency; sponsored blog; disclosure |
2024 |
The effects of sponsorship disclosure in
short-form video: A moderated mediation model of sponsorship literacy and perceived features of sponsored short-form video |
Computers in Human Behavior |
Short-form video; Persuasion knowledge; Sponsorship disclosure; Sponsorship literacy; Features of sponsored short-form video; TikTok |
2024 |
Parasocial relationships with micro-influencers:
do sponsorship disclosure and electronic
word-of-mouth disrupt? |
Internet Research |
Micro-influencer; Parasocial relationship; Sponsorship disclosure; Electronic
word-of-mouth; Customer engagement; Brand preferences; Purchase intention |
2024 |
Consumers’ ambiguous perceptions of advertising disclosures in influencer marketing: Disentangling the effects on current and future social media engagement |
Electronic Markets |
Advertising Psychology; Consumer Behavior; Marketing; Public Engagement with Science; Public Relations; Social Influence |
2024 |
Influencer marketing on Instagram—The optimal disclosure strategy from influencers’ and marketers’ perspectives |
Electronic markets |
Advertising Psychology; Marketing; Media Ethics; Public Relations; Social Influence;
Social Media |
2024 |
Influencer storefronts: impact of social media advertising disclosures on purchases |
Journal of Systems and Information Technology |
Influencer marketing, Influencer advertising; Advertising disclosure; Social media storefronts; Social media use; Social media engagement; Consumer engagement;
e-commerce sales |
2025 |
Commercialization of influencer content on social media: the roles of parasocial relationships and sponsorship disclosures |
Journal of Strategic Marketing |
Commercial orientation; influencer marketing; parasocial relationship; social media; social media influencer; sponsorship disclosure |
2025 |
Exploring the effectiveness of digital manipulation disclosures for Instagram posts on source credibility and authenticity of social media influencers |
International Journal of Advertising |
Authenticity credibility; digital manipulation disclosure; product involvement; social media influencers |
2025 |
Influencer self-disclosure practices on Instagram: A multi-country longitudinal study |
Online Social Networks and Media |
Influencer marketing; Advertising disclosure; Instagram; Self-disclosure practices; Legal compliance |
2025 |
Crafting green influence: The role of
self-disclosure and influencer type in
generation Z’s Pro-environmental engagement |
Journal of Business Research |
Self-disclosure; Influencer type; Environmental responses; Parasocial relationships; Perceived appropriateness;
Gen Z; Gender difference |
3. Findings
3.1. Theoretical Frameworks Guiding Disclosure Research
Much of the research builds on the Persuasion Knowledge Model (PKM), which refers to individuals’ awareness and understanding of the persuasive intent behind marketing messages, shaping how they interpret and respond to such content (Beckert et al., 2021; Boerman, 2020; Van Reijmersdal et al., 2023). Several studies extend beyond PKM by employing Parasocial Relationship Theory, which describes the one-sided, emotionally invested relationships that audiences develop with media figures or influencers, helping to buffer negative effects of disclosures (Breves et al., 2021; Lou et al., 2020). Others incorporate the concept of transparency perception—the extent to which audiences believe that the influencer or brand is open and honest about sponsorship—as a key explanatory factor. Related frameworks such as Authenticity Management examine how influencers balance commercial content with relational trust (AlRabiah et al., 2022; Chen et al., 2023), while Congruence Theory highlights the role of influencer-product fit (De Cicco et al., 2021). In youth-focused research, Theory of Mind has been used to explain developmental differences in disclosure recognition (Castonguay, 2021). Collectively, these frameworks underscore that disclosure effects are driven by multiple psychological and relational mechanisms.
3.2. Message and Disclosure Characteristics
Several studies emphasize that the manner in which sponsorship is disclosed strongly influences consumer responses. Standardized disclosures such as Instagram’s Paid Partnership tag improve recognition and brand recall but do not necessarily enhance parasocial interaction (Boerman, 2020). Related work shows that the prominence of a disclosure, whether it is platform- or influencer-initiated (Karagür et al., 2022), and the intensity of users’ platform engagement (Saternus et al., 2022) can significantly shape outcomes. Importantly, disclosure effects may also operate in dual directions, producing skepticism through persuasion knowledge while simultaneously fostering trust through perceived transparency (Van Reijmersdal et al., 2023). Subtler or less explicit disclosures may help sustain engagement, though often at the cost of transparency (Al-Hasan, 2024). Beyond textual cues, message framing and design further moderate responses: two-sided messages can enhance authenticity and credibility (Lee & Johnson, 2021), and visual strategies such as increasing product salience have been shown to reduce skepticism and offset negative effects of disclosure (Brüns & Meißner, 2023).
3.3. Audience and Contextual Moderators
Disclosure effects are highly contingent on audience characteristics. Adolescents are more likely than adults to perceive disclosures negatively, showing weaker brand evaluations when sponsorship is recognized (Castonguay, 2021; De Jans et al., 2020; Van Reijmersdal et al., 2023). At the same time, outcomes also depend on contextual factors. Perceptions of appropriateness are central: excessive self-disclosure is often judged as inauthentic, reducing trust and purchase intention (AlRabiah et al., 2022). Usage intensity further differentiates responses, with heavy Instagram users generally evaluating disclosed posts more positively than lighter users (Saternus et al., 2022). Finally, individual personality traits, such as materialism (Kim et al., 2021) or emotional intensity (Wang et al., 2022), can amplify or buffer disclosure effects, underscoring the complex interplay of demographic, contextual, and psychological factors.
3.4. Psychological Mechanisms and Mediators
The literature consistently identifies credibility, trust, and empathy as mediators of disclosure effects. Disclosures often enhance credibility, which in turn increases purchase intentions (Sesar et al., 2022). Parasocial relationships reduce resistance and buffer negative responses (Breves et al., 2021; Sheng et al., 2024). Studies also show that disclosures can improve perceived transparency, which sometimes offsets persuasion knowledge activation (Van Reijmersdal et al., 2023). Conversely, inappropriate or excessive self-disclosure by influencers is often judged as inauthentic, reducing trust and purchase intent (AlRabiah et al., 2022). These findings suggest that relational and psychological mechanisms are central to explaining why disclosures can have both positive and negative effects.
3.5. Outcomes: Immediate versus Long-Term Effect
While disclosures frequently reduce short-term outcomes such as ad effectiveness, brand attitudes, and purchase intentions (De Cicco et al., 2021; Wang et al., 2022) some evidence points to positive long-term consequences. Waltenrath (2024) shows that while disclosed posts generate lower immediate engagement, they enhance long-term trust and credibility, leading to stronger engagement with subsequent non-sponsored content. Similarly, transparent disclosures can buffer the negative impact of commercialization on parasocial relationships (Lim et al., 2025). These findings reconcile contradictory results by highlighting the importance of distinguishing between immediate and sustained effects of disclosure.
For influencers, effective authenticity management involves striking a balance between transparency and creative content design (Audrezet et al., 2020). Explicit disclosures, when paired with narrative strategies or enhanced by visual salience, can sustain or even increase engagement (Brüns & Meißner, 2023; Zhou et al., 2021). At the same time, overly detailed or inappropriate self-disclosure may erode trust (AlRabiah et al., 2022). Successful influencers are those who integrate disclosure seamlessly into their content while maintaining authenticity, contextual relevance, and consistency with their established persona.
To synthesize these insights, Table 2 summarizes the key psychological mechanisms, moderating factors, and short- versus long-term outcomes identified across the reviewed studies, offering an integrative framework for understanding how sponsorship disclosures operate in social media influencer marketing.
Table 2. Conceptual framework linking mechanisms, moderators, and outcomes of sponsorship disclosure.
Category |
Key Factors / Variables |
Role in Disclosure Effects |
Representative Studies (2020-2025) |
Psychological Mechanisms |
Persuasion Knowledge, Transparency Perception, Credibility, Trust, Parasocial Relationship, Empathy |
Mediate consumers’ recognition of persuasion and shape cognitive/affective responses to sponsorship |
Beckert et al. (2021);
Breves et al. (2021);
Van Reijmersdal et al. (2023) |
Message Characteristics |
Disclosure Type (explicit vs. subtle), Message Framing (one- vs. two-sided), Visual Salience |
Influence how sponsorship is recognized and how persuasive intent is evaluated |
Boerman (2020);
Brüns & Meißner (2023);
Lee & Johnson (2021) |
Audience Moderators |
Age, Platform Usage Intensity, Materialism, Emotional Intensity |
Determine differential sensitivity to disclosure cues and persuasion knowledge activation |
De Jans et al. (2020);
Wang et al. (2022);
Saternus et al. (2022) |
Contextual Moderators |
A Cultural Fit, Influencer-Product Congruence, Algorithmic Visibility |
Shape perceived appropriateness and authenticity of disclosed content |
Zhou et al. (2021);
Musiyiwa & Jacobson (2023);
De Cicco et al. (2021) |
Short-Term Outcomes |
Ad Recognition, Brand Attitude, Purchase Intention |
Often negative or neutral in immediate evaluations |
De Cicco et al. (2021);
Wang et al. (2022) |
Long-Term Outcomes |
Trust, Credibility, Engagement, Relationship Strength |
Typically, positive when transparency and authenticity are sustained |
Waltenrath (2024);
Lim et al. (2025) |
4. Implications
For regulators, standardized disclosures such as Instagram’s Paid Partnership label have been shown to increase advertising recognition and brand recall (Boerman, 2020). Yet their effectiveness varies across audiences. Adolescents, for example, often respond with more negative brand attitudes when sponsorship is disclosed, whereas adults show less pronounced effects (De Jans et al., 2020; van der Bend et al., 2023). This underscores the importance of age-sensitive regulatory frameworks that consider developmental differences in persuasion processing. In addition, structural challenges such as algorithmic de-prioritization and shadow-banning discourage influencers from complying with disclosure guidelines (Musiyiwa & Jacobson, 2023). Addressing these barriers requires regulators not only to refine disclosure standards but also to push for greater algorithmic transparency and accountability from platforms.
In terms of the brands, the central task lies in selecting influencers whose characteristics align with both the product and the target audience. Strong parasocial bonds between influencers and followers can reduce consumer resistance and enhance trust even when sponsorship is disclosed (Breves et al., 2021; Sheng et al., 2024). Cultural alignment amplifies these effects, as illustrated by findings that national identity cues in Chinese contexts can strengthen trust and engagement (Wang et al., 2022). Brands should therefore assess influencer-audience fit in terms of relational closeness, cultural resonance, and product congruence. Moreover, while disclosures may sometimes undermine short-term engagement, transparent communication can build enduring credibility and strengthen future brand relationships (Waltenrath, 2024).
Limitations and Future Research
Despite the growing body of research on sponsorship disclosure, several limitations remain that require further investigation. Methodologically, much of the current evidence is derived from short-term experiments or cross-sectional surveys, designs that are insufficient to capture the enduring consequences of repeated disclosure exposure (Beckert et al., 2021; De Cicco et al., 2021). Longitudinal research is therefore needed to examine how disclosures shape trust, engagement, and purchase behavior over time, particularly in light of recent evidence that immediate and long-term effects may diverge (Waltenrath, 2024).
The scope of existing work is also limited in terms of platform coverage. Research has concentrated largely on Instagram, while rapidly expanding environments such as TikTok and other short-form video services remain comparatively underexplored (Liu et al., 2024; van der Bend et al., 2023). Given the centrality of these platforms to younger audiences, systematic investigation of their unique affordances, disclosure practices, and user interpretations is especially urgent.
Another limitation concerns potential language and regional bias in the reviewed literature. Most of the studies included in this review were published in English and conducted in Western or East Asian contexts, which may limit the generalizability of findings to other cultural and linguistic settings. This bias reflects the dominance of English-language journals in the academic publishing landscape and the uneven distribution of research resources across regions. Future work should actively incorporate studies published in other languages and from underrepresented markets to capture a more diverse range of consumer perspectives, regulatory environments, and influencer practices.
Taken together, these limitations point to the need for more diverse methodologies and broader research contexts to advance the field. Addressing them will not only enrich our understanding of sponsorship disclosure but also provide more robust guidance for policymakers, brands, and influencers navigating an increasingly complex digital advertising environment. In this sense, the trajectory of future research will play a decisive role in clarifying how disclosures function across time, cultures, and platforms, and in shaping practices that balance transparency, consumer protection, and the sustainability of influencer marketing (Beckert et al., 2021; Brescia et al., 2023; Goh & Wilk, 2024; Liu et al., 2024; Musiyiwa & Jacobson, 2023; van der Bend et al., 2023; Waltenrath, 2024).