inclusion criteria: adults residing in the united states aged 18 years or older. provision of documentation of positive sars-cov-2 testing (via rt-pcr, rapid antigen testing) performed less than 7 days before screening, either via direct upload or confirmation from pcp. electronic secure document upload; allowing stri personnel to contact the pcp to confirm diagnosis; or allowing stri personnel to contact the laboratory where the rt-pcr analysis was performed initial date of onset of covid-19 signs/symptoms 7 days or less from date of stri screening and randomization (i.e., day 0). during screening (day 0): participant-reported response of "mild" or "moderate" in response to the question "overall, how severe were your infection symptoms today?" (flu-pro plus global additional daily diary items question 1) during prescreening, participant self-reported response of "a little worse" or "somewhat worse" or "much worse" or "about the same" in response to the question "overall, how were your infection symptoms today compared to yesterday?" (flu-pro plus global additional daily diary items question 2) during prescreening, participant-reported response of "no" in response to the question "have you returned to your usual health today?" (flu-pro plus global additional daily diary items question 6) at least two participant self-reported responses of "somewhat," "quite a bit," or "very much" in any flu-pro plus domain other than smell and taste (i.e., nose, throat, eyes, chest/respiratory, head, gastrointestinal, or body/systemic domains) ability to self-measure and self-report body temperature, and peripheral oxygen saturation (with stri provided thermometer and stri provided pulse oximeter). provision of signed and dated electronic informed consent form (via 21 cfr part 11 compliant platform). provision of participant's primary care physician (pcp) name and phone number. consent to allow stri personnel to contact pcp for any reason and discuss participant's medical history and/or obtain participant's medical records. stated willingness to comply with all study procedures and availability for the duration of the study, including intent to comply with lifestyle considerations throughout study duration. ability to take oral medication and be willing to adhere to the stri intervention product (stri formula or placebo as capsules) regimen. ability to use the internet daily and check email daily. ability and consent to send and receive sms text messages via cellular phone. provision of information (name, email address, and cellular phone number) of an emergency contact (e.g., family member/friend/colleague) willing to communicate with stri personnel in case the participant deteriorates. willingness to discontinue any dietary supplement that contains any active ingredient in stri formula (ascorbic acid, cholecalciferol, zinc, copper, quercetin, hesperidin, caffeic acid, epigallocatechin gallate, bovine lactoferrin) for the duration of the study. for men and women with child-bearing potential (as defined below), willingness to use adequate contraception for at least 100 days after beginning the study.

inclusion criteria: adults residing in the united states aged 18 years or older. provision of documentation of positive sars-cov-2 testing (via rt-pcr, rapid antigen testing) performed less than 7 days before screening, either via direct upload or confirmation from pcp. electronic secure document upload; allowing stri personnel to contact the pcp to confirm diagnosis; or allowing stri personnel to contact the laboratory where the rt-pcr analysis was performed initial date of onset of covid-19 signs/symptoms 7 days or less from date of stri screening and randomization (i.e., day 0). during screening (day 0): participant-reported response of "mild" or "moderate" in response to the question "overall, how severe were your infection symptoms today?" (flu-pro plus global additional daily diary items question 1) during prescreening, participant self-reported response of "a little worse" or "somewhat worse" or "much worse" or "about the same" in response to the question "overall, how were your infection symptoms today compared to yesterday?" (flu-pro plus global additional daily diary items question 2) during prescreening, participant-reported response of "no" in response to the question "have you returned to your usual health today?" (flu-pro plus global additional daily diary items question 6) at least two participant self-reported responses of "somewhat," "quite a bit," or "very much" in any flu-pro plus domain other than smell and taste (i.e., nose, throat, eyes, chest/respiratory, head, gastrointestinal, or body/systemic domains) ability to self-measure and self-report body temperature, and peripheral oxygen saturation (with stri provided thermometer and stri provided pulse oximeter). provision of signed and dated electronic informed consent form (via 21 cfr part 11 compliant platform). provision of participant's primary care physician (pcp) name and phone number. consent to allow stri personnel to contact pcp for any reason and discuss participant's medical history and/or obtain participant's medical records. stated willingness to comply with all study procedures and availability for the duration of the study, including intent to comply with lifestyle considerations throughout study duration. ability to take oral medication and be willing to adhere to the stri intervention product (stri formula or placebo as capsules) regimen. ability to use the internet daily and check email daily. ability and consent to send and receive sms text messages via cellular phone. provision of information (name, email address, and cellular phone number) of an emergency contact (e.g., family member/friend/colleague) willing to communicate with stri personnel in case the participant deteriorates. willingness to discontinue any dietary supplement that contains any active ingredient in stri formula (ascorbic acid, cholecalciferol, zinc, copper, quercetin, hesperidin, caffeic acid, epigallocatechin gallate, bovine lactoferrin) for the duration of the study. for men and women with child-bearing potential (as defined below), willingness to use adequate contraception for at least 100 days after beginning the study.

inclusion criteria: 1. adults residing in the united states aged 18 years or older. 2. provision of documentation of positive sars-cov-2 testing (via rt-pcr, rapid antigen testing) performed less than 7 days before screening, either via direct upload or confirmation from pcp. 1. electronic secure document upload; 2. allowing stri personnel to contact the pcp to confirm diagnosis; or 3. allowing stri personnel to contact the laboratory where the rt-pcr analysis was performed 3. initial date of onset of covid-19 signs/symptoms 7 days or less from date of stri screening and randomization (i.e., day 0). 4. during screening (day 0): 1. participant-reported response of "mild" or "moderate" in response to the question "overall, how severe were your infection symptoms today?" (flu-pro plus global additional daily diary items question 1) 2. during prescreening, participant self-reported response of "a little worse" or "somewhat worse" or "much worse" or "about the same" in response to the question "overall, how were your infection symptoms today compared to yesterday?" (flu-pro plus global additional daily diary items question 2) 3. during prescreening, participant-reported response of "no" in response to the question "have you returned to your usual health today?" (flu-pro plus global additional daily diary items question 6) 4. at least two participant self-reported responses of "somewhat," "quite a bit," or "very much" in any flu-pro plus domain other than smell and taste (i.e., nose, throat, eyes, chest/respiratory, head, gastrointestinal, or body/systemic domains) 5. ability to self-measure and self-report body temperature, and peripheral oxygen saturation (with stri provided thermometer and stri provided pulse oximeter). 6. provision of signed and dated electronic informed consent form (via 21 cfr part 11 compliant platform). 7. provision of participant's primary care physician (pcp) name and phone number. 8. consent to allow stri personnel to contact pcp for any reason and discuss participant's medical history and/or obtain participant's medical records. 9. stated willingness to comply with all study procedures and availability for the duration of the study, including intent to comply with lifestyle considerations throughout study duration. 10. ability to take oral medication and be willing to adhere to the stri intervention product (stri formula or placebo as capsules) regimen. 11. ability to use the internet daily and check email daily. 12. ability and consent to send and receive sms text messages via cellular phone. 13. provision of information (name, email address, and cellular phone number) of an emergency contact (e.g., family member/friend/colleague) willing to communicate with stri personnel in case the participant deteriorates. 14. willingness to discontinue any dietary supplement that contains any active ingredient in stri formula (ascorbic acid, cholecalciferol, zinc, copper, quercetin, hesperidin, caffeic acid, epigallocatechin gallate, bovine lactoferrin) for the duration of the study. 15. for men and women with child-bearing potential (as defined below), willingness to use adequate contraception for at least 100 days after beginning the study.

inclusion criteria: 1. adults residing in the united states aged 18 years or older. 2. provision of documentation of positive sars-cov-2 testing (via rt-pcr, rapid antigen testing) performed less than 7 days before screening, either via direct upload or confirmation from pcp. 1. electronic secure document upload; 2. allowing stri personnel to contact the pcp to confirm diagnosis; or 3. allowing stri personnel to contact the laboratory where the rt-pcr analysis was performed 3. initial date of onset of covid-19 signs/symptoms 7 days or less from date of stri screening and randomization (i.e., day 0). 4. during screening (day 0): 1. participant-reported response of "mild" or "moderate" in response to the question "overall, how severe were your infection symptoms today?" (flu-pro plus global additional daily diary items question 1) 2. during prescreening, participant self-reported response of "a little worse" or "somewhat worse" or "much worse" or "about the same" in response to the question "overall, how were your infection symptoms today compared to yesterday?" (flu-pro plus global additional daily diary items question 2) 3. during prescreening, participant-reported response of "no" in response to the question "have you returned to your usual health today?" (flu-pro plus global additional daily diary items question 6) 4. at least two participant self-reported responses of "somewhat," "quite a bit," or "very much" in any flu-pro plus domain other than smell and taste (i.e., nose, throat, eyes, chest/respiratory, head, gastrointestinal, or body/systemic domains) 5. ability to self-measure and self-report body temperature, and peripheral oxygen saturation (with stri provided thermometer and stri provided pulse oximeter). 6. provision of signed and dated electronic informed consent form (via 21 cfr part 11 compliant platform). 7. provision of participant's primary care physician (pcp) name and phone number. 8. consent to allow stri personnel to contact pcp for any reason and discuss participant's medical history and/or obtain participant's medical records. 9. stated willingness to comply with all study procedures and availability for the duration of the study, including intent to comply with lifestyle considerations throughout study duration. 10. ability to take oral medication and be willing to adhere to the stri intervention product (stri formula or placebo as capsules) regimen. 11. ability to use the internet daily and check email daily. 12. ability and consent to send and receive sms text messages via cellular phone. 13. provision of information (name, email address, and cellular phone number) of an emergency contact (e.g., family member/friend/colleague) willing to communicate with stri personnel in case the participant deteriorates. 14. willingness to discontinue any dietary supplement that contains any active ingredient in stri formula (ascorbic acid, cholecalciferol, zinc, copper, quercetin, hesperidin, caffeic acid, epigallocatechin gallate, bovine lactoferrin) for the duration of the study. 15. for men and women with child-bearing potential (as defined below), willingness to use adequate contraception for at least 100 days after beginning the study.

inclusion criteria: 1. adults residing in the united states aged 18 years or older. 2. provision of documentation of positive sars-cov-2 testing (via rt-pcr, rapid antigen testing) performed less than 7 days before screening, either via direct upload or confirmation from pcp. 1. electronic secure document upload; 2. allowing stri personnel to contact the pcp to confirm diagnosis; or 3. allowing stri personnel to contact the laboratory where the rt-pcr analysis was performed 3. initial date of onset of covid-19 signs/symptoms 7 days or less from date of stri screening and randomization (i.e., day 0). 4. during screening (day 0): 1. participant-reported response of "mild" or "moderate" in response to the question "overall, how severe were your infection symptoms today?" (flu-pro plus global additional daily diary items question 1) 2. during prescreening, participant self-reported response of "a little worse" or "somewhat worse" or "much worse" or "about the same" in response to the question "overall, how were your infection symptoms today compared to yesterday?" (flu-pro plus global additional daily diary items question 2) 3. during prescreening, participant-reported response of "no" in response to the question "have you returned to your usual health today?" (flu-pro plus global additional daily diary items question 6) 4. at least two participant self-reported responses of "somewhat," "quite a bit," or "very much" in any flu-pro plus domain other than smell and taste (i.e., nose, throat, eyes, chest/respiratory, head, gastrointestinal, or body/systemic domains) 5. ability to self-measure and self-report body temperature, and peripheral oxygen saturation (with stri provided thermometer and stri provided pulse oximeter). 6. provision of signed and dated electronic informed consent form (via 21 cfr part 11 compliant platform). 7. provision of participant's primary care physician (pcp) name and phone number. 8. consent to allow stri personnel to contact pcp for any reason and discuss participant's medical history and/or obtain participant's medical records. 9. stated willingness to comply with all study procedures and availability for the duration of the study, including intent to comply with lifestyle considerations throughout study duration. 10. ability to take oral medication and be willing to adhere to the stri intervention product (stri formula or placebo as capsules) regimen. 11. ability to use the internet daily and check email daily. 12. ability and consent to send and receive sms text messages via cellular phone. 13. provision of information (name, email address, and cellular phone number) of an emergency contact (e.g., family member/friend/colleague) willing to communicate with stri personnel in case the participant deteriorates. 14. for men and women with child-bearing potential (as defined below), willingness to use adequate contraception for at least 90 days after completing self-administration of the stri intervention product.

inclusion criteria: 1. adults residing in the united states aged 18 years or older. 2. provision of documentation of positive sars-cov-2 testing (via rt-pcr, rapid antigen testing) performed less than 7 days before screening, either via direct upload or confirmation from pcp. 1. electronic secure document upload; 2. allowing stri personnel to contact the pcp to confirm diagnosis; or 3. allowing stri personnel to contact the laboratory where the rt-pcr analysis was performed 3. initial date of onset of covid-19 signs/symptoms 7 days or less from date of stri screening and randomization (i.e., day 0). 4. during screening (day 0): 1. participant-reported response of "mild" or "moderate" in response to the question "overall, how severe were your infection symptoms today?" (flu-pro plus global additional daily diary items question 1) 2. during prescreening, participant self-reported response of "a little worse" or "somewhat worse" or "much worse" or "about the same" in response to the question "overall, how were your infection symptoms today compared to yesterday?" (flu-pro plus global additional daily diary items question 2) 3. during prescreening, participant-reported response of "no" in response to the question "have you returned to your usual health today?" (flu-pro plus global additional daily diary items question 6) 4. at least two participant self-reported responses of "somewhat," "quite a bit," or "very much" in any flu-pro plus domain other than smell and taste (i.e., nose, throat, eyes, chest/respiratory, head, gastrointestinal, or body/systemic domains) 5. ability to self-measure and self-report body temperature, and peripheral oxygen saturation (with stri provided thermometer and stri provided pulse oximeter). 6. provision of signed and dated electronic informed consent form (via 21 cfr part 11 compliant platform). 7. provision of participant's primary care physician (pcp) name and phone number. 8. consent to allow stri personnel to contact pcp for any reason and discuss participant's medical history and/or obtain participant's medical records. 9. stated willingness to comply with all study procedures and availability for the duration of the study, including intent to comply with lifestyle considerations throughout study duration. 10. ability to take oral medication and be willing to adhere to the stri intervention product (stri formula or placebo as capsules) regimen. 11. ability to use the internet daily and check email daily. 12. ability and consent to send and receive sms text messages via cellular phone. 13. provision of information (name, email address, and cellular phone number) of an emergency contact (e.g., family member/friend/colleague) willing to communicate with stri personnel in case the participant deteriorates. 14. for men and women with child-bearing potential (as defined below), willingness to use adequate contraception for at least 90 days after completing self-administration of the stri intervention product.